Li XF, Dai LYAcute central cord syndrome: injury mechanisms and stress features. [Journal Article, Research Support,Non-U.S. Govt]Spine (Phila Pa 1976) 2010 Sep 1; 35(19):E955-64.Numerical techniques were used to study the mechanisms of acute central cord syndrome.To analyze thefeatures of stress distribution in the cervical cord under different injury conditions using finite element modelof the cervical cord and to improve the understanding of the possible pathogenesis of acute central cordsyndrome.Acute central cord spinal injury was initially attributed to hemorrhagic damage to the centralportion of the spinal cord, but recent histopathologic studies showed that it was predominantly a whitematter injury. The precise anatomic location of neuronal injury and the etiology of the clinical manifestationwere poorly understood.Cervical cord injury was simulated using a finite element model of the cervicalenlargement described previously, with the model loaded under 3 traumatic postures: neutral, flexion, andextension. Five traumatic conditions were simulated and analyzed: hyperextension with the pinch forcedirected to the anterior (A) or posterior (B); flexion injuries (C), vertical compression with the pinch forcedirected to the anterior (D) or posterior (E). After simulation, several representative cross-sections of eachtraumatic pattern were selected. In each cross-section, the average von Mises stress of 9 regions, such asanterior funiculus, lateral part of the lateral funiculus, medial part of the lateral funiculus, lateral part of theposterior funiculus, medial part of the posterior funiculus, anterior horn, the bottom of anterior horn, thecervix cornu posterioris, the caput cornu posterioris, and the apex cornu posterioris was recorded.Highlocalized stress occurred at the portion under compression injury and the level above it. High localized stresstended to occur at the lateral part of the anterior horn motor neurons innervating the hand muscles intraumatic conditions A and D. Under conditions A, D, and E, the average localized stress at the anterior andposterior horn of the gray matter was higher than that at the white matter in all selected cross-sections, andthe stress was higher at the anterior funiculus, the medial part of the lateral funiculus, and the lateral partof the posterior funiculus in the white matter. Under conditions B and C, the differences of the localizedstress between the gray and the white matter were not as significant as under conditions A, D, and E, andthe stress was lower at the medial part of the lateral funiculus than that at the lateral part of the posteriorfuniculus. Under all traumatic conditions, the average stress at the lateral part was higher than that at themedial part of the posterior funiculus.Three common traumatic patterns: hyperextension, flexion, andvertical compression, could be the possibly underlying injury mechanisms of the central cervical cordsyndrome according to the results of the current finite element analysis. The stress features under differentinjury conditions were not in complete accord. High stress mainly occurred at the posterior horn, theanterior horn, and the adjacent white matter. The centermost lesion was not common in mild central cordinjuries. The upper extremity weakness should be ascribed to the damage at the corticospinal tract and themotor neurons in the anterior horn. Hyperpathia probably resulted from injuries to the posterior horn, theanterior funiculus, and the fasciculus cuneatus. Just as there are varieties of the localized stress features incentral cord injuries, variations in clinical presentations were common.van der Graaff MM, de Jong JM, Baas F, de Visser MUpper motor neuron and extra-motor neuron involvement in amyotrophic lateral sclerosis: a clinical andbrain imaging review. [Journal Article, Research Support, Non-U.S. Govt, Review]Neuromuscul Disord 2009 Jan; 19(1):53-8.There is an ongoing discussion whether ALS is primarily a disease of upper motor neurons or lower motorneurons. We undertook a review to assess how new insights have contributed to solve this controversy. Forthis purpose we selected relevant publications from 1995 onwards focussing on (1) primary targets anddisease progression in ALS and variants of ALS, (2) brain imaging markers for upper motor neuron lesion,and (3) evidence for ALS being a multisystem disorder. Clinically, upper motor and lower motor neuronsymptoms can occur in any order over time. Brain imaging markers show upper motor neuron involvementin early disease. Overlap syndromes of ALS and dementia, and involvement of autonomic and sensorynerves occur frequently. PET/SPECT scans, functional MRI and voxel based morphometry studies clearlyshow abnormalities in extra-motor areas of the brain. Pathologically, the 43 kDa TAR DNA-binding protein(TDP-43) provides a clue to these overlapping disorders. In conclusion, evidence accumulates that ALS is amultisystem disorder rather than a pure lower and/or upper motor neuron disorder.
Campanini I, Merlo A, Farina DMotor unit discharge pattern and conduction velocity in patients with upper motor neuron syndrome.[Journal Article, Research Support, Non-U.S. Govt]J Electromyogr Kinesiol 2009 Feb; 19(1):22-9.Motor unit properties were analyzed in patients with upper motor neuron syndrome (UMNS). Multi-channelsurface electromyographic (EMG) signals were recorded for 300s from the biceps brachii muscle of sevenmale subacute patients (time from lesion, mean+/-SE, 4.9+/-1.0 months). In three patients, both armswere investigated, leading to 10 recorded muscles. Patients were analyzed in rest-like condition with motorunits activated due to pathological muscle overactivity. For a total of 12 motor units, the complete dischargepattern was extracted from EMG decomposition. Interpulse interval variability was 7.8+/-0.9%. At minimumdischarge rate (6.4+/-0.4 pulses per second, pps), conduction velocity was smaller than at maximumdischarge rate (12.0+/-0.9pps) in all motor units (3.60+/-0.21m/s vs. 3.84+/-0.20m/s). Conductionvelocity changed by 1.35+/-0.48% (different from zero, P<0.01) for each increase of 1pps in discharge rate.It was concluded that conduction velocity of low-threshold motor units in subacute patients with UMNS hadsimilar values as reported in healthy subjects and was positively correlated to instantaneous discharge rate(velocity recovery function of muscle fibers).Brown JARecovery of motor function after stroke. [Journal Article, Review]Prog Brain Res 2006.:223-8.Improvement of motor activity may occur after stroke. It may be because of recovery of marginallyfunctional neurons. It may also occur by relearning, a process that strengthens existing pathways and maylead to new functional or structural changes- neuroplasticity. Clinical investigation into the treatment ofchronic pain after thalamic infarction has shown improvement in motor function when pain relief is achievedwith motor cortex stimulation. More recently, laboratory studies in rats and primates demonstrate significantimprovement in forelimb reaching tasks in rats and primates after induced ischemic cortical infarction whenrehabilitation is paired with stimulation of the injured cortex and cortical margin at low frequency (50 Hz).Structural changes have also been observed. Dendritic density in layer V of the cortex near the lesionincreases after cortical stimulation, consistent with a restorative cortical plasticity. Also, stimulationcombined with rehabilitation increases the area of the injured cortex from which movements can be evokedin response to stimulation of the injured cortex in rats. Unilateral cortical stimulation reduces secondarycortical hyperexcitability in the impaired hemisphere after stroke. These findings form the basis for the firstclinical study motor cortex stimulation after chronic stroke in humans. A prospective, randomizedmulticenter study of subthreshold motor cortical electrical stimulation during rehabilitation in patients hasbeen completed. The eight patients entered into this study had weakness from a stroke that occurred atleast four months before enrollment. Results demonstrate that the treatment is safe. In addition, there wassignificant improvement in upper extremity function. These improvements persisted through the 12-weekfollow-up assessment period after completion of stimulation and rehabilitation. Recently, non-invasivetranscranial magnetic stimulation of the motor cortex demonstrates improvements in hand function thatpersist after stimulation for at least 25 minutes. Such work represents a paradigm shift in the approachtowards rehabilitation of the stroke-injured brain away from pharmacologic flooding of neuronal receptors,instead towards targeted physiologic stimulation.Brunelli GResearch on the possibility of overcoming traumatic paraplegia and its first clinical results. [Journal Article,Review]Curr Pharm Des 2005; 11(11):1421-8.The interruption of the continuity of the spinal cord is still an incurable lesion. In contrast with the peripheralnerves, the axons regenerating from the mother cells of the brain do not progress inside the cord. Thereasons of this "non-permissiveness" are still unclear. This article describes the attempts of the author toovercome this non-permissiveness by means of a research that began in 1980 on rats, and continued since1993 on monkeys. Results of the research on experimental animals were good and convincing so that thisoperation has been performed on fully informed human being volunteers affected by total severance of thecord between T8 and T11. Results of the first clinical cases are presented regarding operations performed
either by rerouting the ulnar nerve to the lower limbs, or connecting the rostral stump of the severed cordwith peripheral nerves of the hip to obtain rudimentary, but efficient, walking. Recovery occurred well inadvance of the expected time, and continued to improve up to allow the first patient operated on byconnecting CNS with PNS to walk with sticks after having walked for some months with a walker. Thisconnection functioned even if the axons activating the single muscles were from mother cells dispersed indifferent regions of the brain cortex. These cells fire together giving selective contraction of diverse muscles.Furthermore, function occurred although the upper motor neuron uses the neurotransmitter glutamate,whereas motor end plates use receptors for acetylcholine. These data are under further investigation todetermine whether the upper motor neuron changes the transmitter, or if the motor end changes itsreceptors (as seems to be by the first results).Woods NN, Brooks LR, Norman GRThe value of basic science in clinical diagnosis: creating coherence among signs and symptoms. [JournalArticle, Research Support, Non-U.S. Govt]Med Educ 2005 Jan; 39(1):107-12.We investigated whether learning basic science mechanisms may have mnemonic value in helping studentsremember signs and symptoms, in comparison with learning the relation between symptoms and diagnosesdirectly.To compare 2 approaches to learning diagnosis: learning how features of various conditions relate tounderlying pathophysiological mechanisms and learning the conditional probabilities of features anddiseases.Undergraduate students (n = 36) were taught 4 disorders (upper motor neuron lesion, lower motorneuron lesion, neuromuscular junction disease and muscular disease), either using basic scienceexplanations or (symptom x disease) probabilities. They were tested with diagnostic cases immediately afterlearning and 1 week later.On the immediate test, there was no difference in the results. One week later, theaccuracy of the mechanism group remained at 0.52, but the performance of the probability group haddropped to 0.43.Knowledge of basic science may have value in clinical diagnosis by helping students recallor reconstruct the relationships between features and diagnoses.Calancie B, Alexeeva N, Broton JG, Molano MRInterlimb reflex activity after spinal cord injury in man: strengthening response patterns are consistent withongoing synaptic plasticity. [Comparative Study, Journal Article, Research Support, Non-U.S. Govt,Research Support, U.S. Govt, P.H.S.]Clin Neurophysiol 2005 Jan; 116(1):75-86.Previous reports from our laboratory have described short-latency contractions in muscles of the distalupper limb following stimulation of lower limb nerves or skin in persons with injury to the cervical spinalcord. It takes 6 or more months for interlimb reflexes (ILR) to appear following acute spinal cord injury(SCI), suggesting they might be due to new synaptic interconnections between lower limb sensory afferentsand motoneurons in the cervical enlargement. In this study, we asked if once formed, the strength of thesesynaptic connections increased over time, a finding that would be consistent with the above hypothesis.Westudied persons with sub-acute and/or chronic cervical SCI. ILR were elicited by brief trains of electricalpulses applied to the skin overlying the tibial nerve at the back of the knee. Responses were quantifiedbased on their presence or absence in different upper limb muscles. We also generated peri-stimulus timehistograms for single motor unit response latency, probability, and peak duration. Comparisons of theseparameters were made in subjects at sub-acute versus chronic stages post-injury.In persons with sub-acuteSCI, the probability of seeing ILR in a given muscle of the forearm or hand was low at first, but increasedsubstantially over the next 1-2 years. Motor unit responses at this sub-acute stage had a prolonged andvariable latency, with a lower absolute response probability, compared to findings from subjects with chronic(i.e. stable) SCI.Our findings demonstrate that interlimb reflex activity, once established after SCI, showssigns of strengthening synaptic contacts between afferent and efferent components, consistent with ongoingsynaptic plasticity.Neurons within the adult human spinal cord caudal to a lesion site are not static, butappear to be capable of developing novel-yet highly efficacious-synaptic contacts following trauma-inducedpartial denervation. In this case, such contacts between ascending afferents and cervical motoneurons donot appear to provide any functional benefit to the subject. In fact their presence may limit the regenerativeeffort of supraspinal pathways which originally innervated these motoneurons, should effort in animalmodels to promote regeneration across the lesion epicenter be successfully translated to humans withchronic SCI.Doherty JG, Burns AS, OFerrall DM, Ditunno JFPrevalence of upper motor neuron vs lower motor neuron lesions in complete lower thoracic and lumbar
spinal cord injuries. [Comparative Study, Journal Article, Research Support, U.S. Govt, Non-P.H.S.]J Spinal Cord Med 2002; 25(4):289-92.To determine the incidence and etiology of lower motor neuron (LMN) vs upper motor neuron (UMN) lesionsin patients with complete thoracic and lumbar spinal cord injuries (SCI).Retrospective chart review.Aregional Model Spinal Cord Injury System center.A consecutive sample of medical records of patients withlower thoracic and upper lumbar (T7-L3) complete SCI admitted from 1979 through 1996 was systematicallyreviewed. Of the 306 patients evaluated, 156 subjects met inclusion criteria. The incidence and etiology ofLMN vs UMN lesions were determined for the following neurologic levels: T7-T9, T10-T12, L1-L3. Lesionswere classified as LMN, UMN, or mixed on the basis of the presence or absence of (1) the bulbocavernosusreflex, (2) lower limb deep tendon reflexes below the neurologic level of injury, and (3) the Babinskisign.The incidences of LMN, UMN, and mixed lesions in the T7-T9, T10-T12, and L1-L3 groups were asfollows: T7-T9 group (7.3% LMN, 85.5% UMN, 7.3% mixed), T10-T12 group (57% LMN, 17.7% UMN,25.3% mixed),L1-L3 group (95.5% LMN, 0.0% UMN, 4.5% mixed). Etiology of injury did not significantlyinfluence the likelihood of a LMN lesion.One cannot determine the type of lesion (UMN vs LMN) on the basisof the neurological level of injury. A detailed clinical examination, including sacral reflexes, is required. Thishas important prognostic and therapeutic implications for bowel, bladder, and sexual function, as well asmobility. Distinguishing UMN lesions from LMN lesions is also essential for evaluating new interventions inclinical trials for UMN pathology.Svantesson U, Takahashi H, Carlsson U, Danielsson A, Sunnerhagen KSMuscle and tendon stiffness in patients with upper motor neuron lesion following a stroke. [Journal Article,Research Support, Non-U.S. Govt]Eur J Appl Physiol 2000 Jul; 82(4):275-9.The objective of this study was to investigate muscle and tendon stiffness in the triceps surae muscles inpatients who had previously had a stroke. The participants were 12 men showing slight to moderate degreesof muscle tonus in the affected leg. All patients showed minimal or no overt clinical motor symptoms, and allwalked without mechanical aid. Muscle strengths in isometric and isokinetic activities were measured, aswas passive resistance during plantarflexion in each leg. Walking speed was also measured. Evaluations ofphysical performance and muscle tone were made. Muscle and tendon stiffness was calculated frommeasurements whilst passively stretching during electrical stimulation, separately for each leg. Musclestrength was significantly higher in the non-affected than in the affected leg. Muscle stiffness wassignificantly higher in the affected leg than in the non-affected leg. Tendon stiffness was significantly higherin the non-affected than in the affected leg. The higher muscle stiffness in the affected leg might enhancethe possibility for storing elastic energy during preactivation. Lower tendon stiffness in the affected legmight reduce the development of fatigue in movements at low velocities.Mulcahey MJ, Smith BT, Betz RREvaluation of the lower motor neuron integrity of upper extremity muscles in high level spinal cord injury.[Clinical Trial, Journal Article, Research Support, Non-U.S. Govt]Spinal Cord 1999 Aug; 37(8):585-91.To evaluate the lower motor neuron (LMN) integrity of upper extremity muscles of persons with hightetraplegia (C1-C4) in order to determine muscles available for stimulation.Fourteen subjects (23 arms)were evaluated for LMN integrity. Muscles that elicited a functional response (grade 3 or better) to surfaceelectrical stimulation were considered to have intact LMN and good candidates for FES. Strength-duration(S-D) curves were generated on muscles that showed weak (less than grade 3) or no response to surfacestimulation. Muscles were considered denervated if S-D curves were discontinuous or depicted steep,increasing amplitude for pulse durations greater than 1 m.Muscles for grasp and release had intact LMN in19 of 23 (83%) arms. The wrist extensors and flexors and pronator were excitable in 17 (74%), 20 (87%)and 19 (83%) arms, respectively. The supinator demonstrated LMN lesion in 80% of the arms. Over 90% ofthe biceps muscles were unresponsive to electrical stimulation and 85% and 87% of the deltoid andsupraspinatus muscles, respectively, were not electrically excitable. The latissimus dorsi and triceps muscleswere typically innervated (78% and 91%, respectively) and slightly more than half (52%) of the pectoralismajor muscles were excitable.These data suggest that application of FES in high tetraplegia for hand andarm function would require augmentation because of the inability to stimulate the elbow flexors, deltoid and
rotator cuff muscles. These data also show that several paralyzed proximal muscles with intact LMN thathave been historically transferred to address shoulder paralysis in other patient populations are available fortransfer and stimulation in the population with high level spinalSvantesson U, Osterberg U, Grimby G, Sunnerhagen KSThe standing heel-rise test in patients with upper motor neuron lesion due to stroke. [Journal Article,Research Support, Non-U.S. Govt]Scand J Rehabil Med 1998 Jun; 30(2):73-80.The objective was to investigate the fatigue process in the triceps surae during the heel-rise test (eccentricand concentric phases) in comparison with a walking test and muscle strength. Eight men with prior strokeand 8 age-matched healthy men participated. The electromyographic activity in form of root mean squareand mean power frequency of the gastrocnemius and soleus muscles were measured and work estimated.Walking speed and maximal peak torque were measured and differed significantly between the patient andreference groups. There were no significant differences between the groups nor legs concerning the numberof heel-rises or work performed. In the eccentric phase, mean power frequency decreased significantly morein the gastrocnemius than in the soleus muscle in the reference group, while mean power frequency in thesoleus muscle tended to decrease more, though non-significantly, in the affected leg. The conclusion is thatthe capacity to perform the heel-rise test in patients with prior stroke is better than plantarflexor peaktorque and walking speed.Svantesson U, Osterberg U, Grimby G, Sunnerhagen KSThe standing heel-rise test in patients with upper motor neuron lesion due to stroke. [Journal Article,Research Support, Non-U.S. Govt]Scand J Rehabil Med 1998 Jun; 30(2):73-80.The objective was to investigate the fatigue process in the triceps surae during the heel-rise test (eccentricand concentric phases) in comparison with a walking test and muscle strength. Eight men with prior strokeand 8 age-matched healthy men participated. The electromyographic activity in form of root mean squareand mean power frequency of the gastrocnemius and soleus muscles were measured and work estimated.Walking speed and maximal peak torque were measured and differed significantly between the patient andreference groups. There were no significant differences between the groups nor legs concerning the numberof heel-rises or work performed. In the eccentric phase, mean power frequency decreased significantly morein the gastrocnemius than in the soleus muscle in the reference group, while mean power frequency in thesoleus muscle tended to decrease more, though non-significantly, in the affected leg. The conclusion is thatthe capacity to perform the heel-rise test in patients with prior stroke is better than plantarflexor peaktorque and walking speed.Herdmann J, Dvorák J, Bock WJMotor evoked potentials in patients with spinal disorders: upper and lower motor neurone affection. [JournalArticle, Research Support, Non-U.S. Govt]Electromyogr Clin Neurophysiol 1992 Jul-Aug; 32(7-8):323-30.Motor evoked potentials (MEP) following magnetoelectric stimulation allow for detection and quantification ofa lesion of the central and peripheral motor pathways. MEP latency is a very sensitive parameter,irrespective whether the lesion affects the upper motor neurone, e.g. in cervical myelopathy, or the lowermotor neurone e.g. in cervical or lumbar radiculopathy. However, an increase of MEP latency alone does notallow for a distinction of either upper motor neurone or lower motor neurone affection. We have thereforescrutinized MEP latency and MEP waveform (amplitude, duration, and number of phases) in normal subjects,as well as in patients with cervical myelopathy (upper motor neurone affection: UMNA) and in patients withradiculopathies (lower motor neurone affection, LMNA). The increase of central motor latency compared tonormal values was significantly higher in UMNA than in LMNA. MEP following transcranial magnetoelectricstimulation were split up and their duration in relation to M-wave duration was significantly increased inpatients with UMNA, yet normal in patients with LMNA. MEP amplitude in relation to M-wave amplitude wassignificantly decreased in patients with UMNA, yet normal in patients with LMNA. We conclude that cervicalmyelopathy and cervical or lumbar radiculopathies lead to changes of MEP waveform, which are specific foreither upper or LMNA. The analysis of amplitude, duration, and number of phases of MEP following
transcranial stimulation increases the diagnostic value of MEP in disorders of the spine affecting the centralor proximal peripheral motor pathways.Palmer JB, Holloway AM, Tanaka EDetecting lower motor neuron dysfunction of the pharynx and larynx with electromyography. [JournalArticle, Research Support, Non-U.S. Govt, Research Support, U.S. Govt, P.H.S.]Arch Phys Med Rehabil 1991 Mar; 72(3):214-8.This study assessed the utility of clinical electromyography (EMG) for detecting lower motor neuron (LMN) orupper motor neuron (UMN) dysfunction affecting the intrinsic muscles of the larynx and pharynx. Twenty-nine subjects were examined; their clinical diagnoses included perioperative nerve injury, cerebral infarction,and lateral medullary infarction. Resting activity, motor unit action potential (MUAP) morphology, and MUAPrecruitment were evaluated in every case. Medical records (excluding EMG data) were analyzed for clinicalevidence of LMN or UMN dysfunction in the intrinsic muscles of the larynx and pharynx. The diagnosis ofLMN dysfunction rested on clinical data consistent with cranial nerve injury, poliomyelitis, Wallenbergsyndrome, or unilateral bulbar palsy. Criteria for UMN dysfunction included previous cerebral (notbrainstem) infarction or mass lesion or the presence of hemiparesis. Electromyographic abnormalities weresignificantly associated with LMN dysfunction (p less than .05), but they were not significantly associatedwith UMN dysfunction. Of the parameters tested, MUAP recruitment was the most sensitive (82%) andspecific (92%).Hömberg V, Stephan KM, Netz JTranscranial stimulation of motor cortex in upper motor neurone syndrome: its relation to the motor deficit.[Journal Article, Research Support, Non-U.S. Govt]Electroencephalogr Clin Neurophysiol 1991 Oct; 81(5):377-88.The purpose of this investigation was to clarify the functional significance of the fastest cortico-motoneuronal connections in chronic upper motor neurone syndromes. Using magneto-electrical stimulationof motor cortex the intactness of cortico-motoneuronal connections was assessed in 51 patients presentingwith variable degrees of impairment. There was a gross correlation between clinical impairment of thepatient and the degree of pathology of cortico-motoneuronal efferents. Covariation of clinical data withtranscranial stimulation was better than covariation with the size of lesion on CT scans. In some patients,however, definite clinical impairment, especially affecting distal fractionated movements, was associatedwith completely normal responses. There was no evidence of response abnormality in distal musclesipsilateral to the hemispheric lesion. The data indicate that motor deficit can exist in the presence of normalcortico-motoneuronal conduction times, showing that intactness of these connections is not a sufficientcondition for preservation of voluntary motor activities. This underlines the importance of other pathways forthe pathogenesis of upper motor neurone syndromes.Swash MWhy are upper motor neuron signs difficult to elicit in amyotrophic lateral sclerosis? [Journal Article, Review]J Neurol Neurosurg Psychiatry 2012 Jun; 83(6):659-62.It is often difficult to identify signs of upper motor neuron lesion in the limbs of patients with amyotrophiclateral sclerosis, in whom there is neurogenic muscle wasting of varying severity. The reasons for this arecomplex and not related simply to the degree of lower motor neuron muscle wasting but, rather, depend onthe pathophysiological abnormalities that develop in response to damage to descending motor pathways andto motor neurons and interneurons in the ventral horns of the spinal cord. The different mechanismsunderlying the clinical phenomenology of the functional motor defect in amyotrophic lateral sclerosis, thatlead to difficulty in detecting classical upper motor neuron signs, are discussed.Noto Y, Kanai K, Misawa S, Shibuya K, Isose S, Nasu S, Sekiguchi Y, Fujimaki Y, Nakagawa M, Kuwabara SDistal motor axonal dysfunction in amyotrophic lateral sclerosis. [Journal Article, Research Support, Non-U.S. Govt]J Neurol Sci 2011 Mar 15; 302(1-2):58-62.
Nerve conduction slowing in amyotrophic lateral sclerosis (ALS) is usually caused by loss of fast motoraxons. We studied the frequency, extent, and distribution of prominently prolonged distal motor latencies inALS. We reviewed results of median, ulnar, and tibial nerve conduction studies in 91 patients with ALS, 24with lower motor neuron disorders, and 36 with axonal neuropathy. Coincidental carpal tunnel syndromewas found for 4 (4.4%) of the ALS patients who were excluded from analyses. Markedly prolonged distallatencies (>125% of the upper limit of normal) were found only in the median nerve of ALS patients (9%),and in none of the disease controls. Excitability studies suggested membrane depolarization in some ALSpatients. Our results show that approximately 10% of ALS patients shows prominently prolonged mediandistal latency, which cannot be explained by axonal loss and carpal tunnel lesion. The distal nerveconduction slowing may partly be caused by membrane depolarization possibly due to motor neuronaldegeneration in ALS. We suggest that recognition of the pattern of distal motor axonal dysfunctionpredominant in the median nerve is clinically important, and could provide additional insights into thepathophysiology of ALS.Wagner G, Klinge H, Sachse MMRamsay Hunt syndrome. [Journal Article, Review]J Dtsch Dermatol Ges 2012 Apr; 10(4):238-44.Ramsay Hunt syndrome is defined as herpes zoster oticus associated with an acute peripheral facial nerveparesis and quite often with other cranial nerve lesions. The combination of motor, sensory and autonomicinvolvement leads to a variety of neurological damage patterns, i. e. facial muscle paresis, hearing andbalance disorders, sensory problems and disturbances of taste as well as lacrimal and nasal secretion.Additional variability of the clinical picture of Ramsay Hunt syndrome is produced by varying patterns of skininvolvement explained by individual anastomoses between cranial and cervical nerves. Knowledge of thesefindings and an early diagnosis of Ramsay Hunt syndrome are important as prognosis of cranial nervedamage depends on the time at which acyclovir-corticosteroid therapy is started.Ratnayake EC, Caldera M, Perera P, Gamage RIsolated trigeminal nerve palsy with motor involvement as a presenting manifestation of multiple sclerosis inan equatorial region - a case report. [Journal Article]Int Arch Med 2012; 5(1):17.ABSTRACT:Isolated cranial nerve palsies are considered to be an uncommon presenting feature of multiplesclerosis. Involvement of the trigeminal nerve, particularly its motor component as part of a clinicallyisolated syndrome of multiple sclerosis has rarely been reported in equatorial regions and no cases havebeen described in Sri Lanka thus far.We report a case of isolated right sided trigeminal nerve palsy (Motorand Sensory) in a 34 year old previously well lady from urban Sri Lanka who was found to havecharacteristic lesions on Magnetic Resonance Imaging highly suggestive of multiple sclerosis.Multiplesclerosis should be considered in the differential diagnosis of patients who present with isolated cranialnerve palsies. Clinicians should have a high index of suspicion when evaluating such patients especially inlow prevalence regions close to the equator. Early recognition and treatment of such a "Clinically IsolatedSyndrome" may prevent early relapse.