Cerebellum is the 2nd largest part of the brain occupyingthe posterior cranial fossa beneath the tentorium cerebellibelonging to a distributed sensori motor network designedfor coordination of willed muscular contractions andmaintenance of body balance.
In voluntary movement› corrects motor irregularities› compares motor “central” intentions to “peripheralperformance”› controls ballistic movements In posture and equilibrium› cooperation with spinal cord, cortex and reticularformation Primarily inhibitory function
DYSARTHRIA NYSTAGMUS DYSTAXIA OF STATION AND GAIT DYSTAXIA OF LIMB MOVEMENTS.Dyssynergia (Decomposition of movements).Dysmetria.Agonist - Antagonist incoordination.Dysdiadochokinesia.Rebound phenomenon.Intention tremor HYPOTONIA
SPEECH Articulation is slow, ataxic, drawling, slurred, jerkyor explosive type. Speech is scanning in nature.
Gaze evoked nystagmus Hemispheric lesion – eyes at rest deviate 10-300toward unaffected side, on attempting to gaze elsewhere, eyes saccadestoward point of fixation Slow component toward resting point Cerebellopontine Angle Tumor – Nystagmus is coarseon looking toward affected side and fine & rapid on gazing to oppt side – BRUNSNYSTAGMUS
May over or under - shoot target with attemptsat fixation ( ocular dysmetria ) In primary position, may see saccadic intrusions(such as macro square – wave jerks ) or primarynystagmus ( incl. vertical, esp up-beat nystagmus )or periodic alternating nystagmus rebound nystagmus can occur with contralateral-beating nystagmus on return of eyes to primaryposition after eccentric gaze evoked nystagmusto one side
STATION Broad based stance Swaying of body Standing on one foot - falls on affected side GAIT Free walking–wide based,clumsy staggering, lurching type of gait Straight line walking Tandem walking
Look for smoothness, accuracy,oscillations, jerkiness. Stops before or overshoots thetarget Intension tremor FINGER TO FINGER TEST(FingerTips in the Midline)FINGER TO NOSE TEST
(DYSDIADOCHOKINESIA) PRONATION ANDSUPINATION TESTUneven excurtion ofaffected side hand THIGH PATTING TESTSlaps irregularly,slowly onthe affected hand FINGER TAPPING TEST.RAPID ALTERNATING MOVEMENT TEST
ARM PULLING TEST(Holmes Rebound Test) patient fails to checkarm’s flight WRIST TAPPING TESTArm oscillates back andforth and overshoots severaltimesOVERSHOOTING AND CHECKING TESTS
PAST POINTING TESTSArm on the affected side deviate outwardstowards the side of lesionThree types of drift of outstretched hands1. Pyramidal drift( pronator or Barre’s sign)Arm sinks downward and there is accompanying pronationof the forearm.2. Parietal driftArm usually rises and strays outward (updrift)3. Cerebellar driftArm drifts mainly outward, either at the same level, risingor less often sinking.
OTHER ADDITIONAL TESTS Tapping in a circle Spiral drawing test Drawing line between two fixed points Macrographia
HEEL-KNEE TEST Heel overshoots the knee sideways and develops a rotaryoscillations as heel approaches the knee While moving down the shin the heel oscillates from side to side. HEEL TAPPING TEST DRAWING A CIRCLE WITH THE LEG
Decrease in resistance to passive movement of musclesrelated to depression of gamma motor neuronactivity INSPECTIONAt rest, assumes a floppy posture(rag doll appearance)while walking, floppy sagging, loose jointed appearance. PASSIVE MOVEMENTIncreased range of joint exertion PENDULOUS MUSCLE STRECH REFLEXESLeg swings to and fro several times
A: Lateral or Hemispheric syndrome B: Midline or Vermis(Rostral vermis) syndrome C :Caudal Vermis(Flocculonodular) syndrome A+B+C :Pancerebellar syndrome
Hemisphere Appendicular ataxia Stroke(Bleed,infarct)Tumor(Astrocytoma)Abscess,multiplesclerosis.Vermis Gait Ataxia Alcoholicdegeneration,midline tumorFlocculonodular lobe Nystagmus,extraocular movementabnormalityTumors(astrocytoma,medulloblastoma,ependymomaPancerebellar All of The Above Drugs,Toxins,paraneoplasticSite of lesion manifestation cause
GAIT CYCLE-period between successive points at whichheel of the same foot strikes the ground.1. STANCE PHASE -foot in contact with the ground, occupies 60-65 %of the cycle.2. SWING PHASE -Begins when toes leave the ground. DOUBLE LIMB SUPPORT -Both feet are in contact with the ground,occupies 20-25% of the walking cycle.
1. Initial Contact› The moment when the foot contacts the ground, heel strike (heelstrike)2. Loading response› The weight is rapidly transferred onto the outstretched limb, thefirst period of double-limb support (foot flat)3. Midstance› The body progresses over a single, stable limb4. Terminal Stance› Progression over the stance limb continues. The body movesahead of the limb and weight is transferred onto the forefoot5. Pre-Swing› A rapid unloading of the limb occurs as weight is transferred ontothe forefoot (toe-off)
1. Initial swing› The thigh begins to advance as the foot comes up fromthe floor.2. Midswing› The thigh continues to advance as the knee begins toextend; the foot clears the ground.3. Terminal Swing› The knee extends; the limb prepares to contact theground for Initial Contact.
Parameters to measure & characterize gait:1. Step length -Distance advanced by one footcompared to the position of the other2. Stride length -Sum of two consecutive step lengthsor the distance advanced by one foot compared toits prior position3. Step time –Time between heel strike of one footto the subsequent heel strike of the contralateralfoot4. Stride time –time for a full gait cycle5. Average Gait velocity - Stride length divided bystride time
1. ANTIGRAVITY SUPPORT-Provided by righting & antigravity reflexes. Postural reflexes depend on afferent, vestibular,somatosensory(Proprioceptive & Tactile) & visual impulses,which are integrated in spinal cord, brainstem & basalganglia2. STEPPNG-Integrated in spinal-midbrain-diencephalic levels. Elicited by contact of sole with a flat surface & shifting ofcenter of gravity- first laterally onto one foot, allowing otherto raised, then forward, allowing the body to move onto theadvancing foot.
3. EQUILIBRIUM- Involves maintenance of balance inrelation to gravity & to the direction of movement inorder to retain a vertical posture. Shifting of Center of gravity ,with activity of highlysensitive postural & righting reflexes, bothperipheral(stretch reflex) & central (vestibulocerebellarreflex).4. PROPULSION- Provided by forward & slightly to oneside & permitting the body to fall a certain distancebefore being checked by support of the leg. Both forward & alternating lateral movements mustoccur.
• Wide base,• unsteadiness,• irregularity of steps,• lateral veering. Steps are uncertain, some short & long, pt compensatethese problem by shortening his steps & shuffling, referredto as “Reeling or Drunken gait” Causes-multiple sclerosis, cerebellar tumors - medulloblastoma,stroke, cerebellar degeneration
“Disturbances in the sensory input to the cerebellum” corrective effects of the Visual system Steppage gait - walks with unusually high steps. Throws out her foot & slams it down on floor in order to increaseproprioceptive feedback. While walking, watches her feet and keep an eye on floor Difficulty is even worse walking backward Romberg’s sign Loss of tendon reflexes Features of Peripheral neuropathy
• Hemiparetic Posture - arm flexed,adducted, internally Rotated & Legextended.• Equinus deformity.• With each step pt tilt pelvis upwardon involved side to aid in lifting toeoff the floor & may swing entireExtremity around semi circle fromhip ( Circumduction ).• Both Stance and swing phase -shortened
Causes– Congenital spastic diplegia (Little’s disease,cerebral palsy), Chronic myelopathies (multiple sclerosis, cervicalspondylosis) Characteristic tightness of Hip adductors causingadduction of the thighs, so that knee may cross,one in front of other, with each step (scissors gait) Pt walk on abnormally narrow base with stiffshuffling gait, dragging both legs, scraping the toes.
Steps are short & slow. Marked compensatory swag of trunk away fromside of advancing leg. Shuffling, scraping sound together with worn areasat toes or shoes – are characteristic Equinus position of feet & heel cord shorteningoften cause pt to walk on tip toe.
• Disorder cause involvement of both corticospinal& proprioceptive pathways ( eg. Vit - B 12deficiency, Multiple Sclerosis) resulting in gait thathas features of both spasticity and ataxia.• Ataxic component may be either cerebellar orsensory. In vit-B 12 deficiency, it is predominentlysensory & in multiple sclerosis – both component.• In amyotrophic lateral sclerosis – b/L foot drop,spasticity result in spastic ataxic gait describedas jiggling or Bobbing with tremulous, bouncing,up & down body movement
• Festinating gait – Pt is stooped, head & neckforward & knees flexed, upper extremities areflexed at shoulders, elbows & wrist but fingers areusually extended.• Gait is slow, stiff & shuffling. pt walks with smallmincing steps.• Difficulty walking may be one of earliest symptom.• Impaired postural reflexes lead to tendency tofall forward (propulsion) which pt tries to avoid bywalking with increasing speed but with very shortsteps.
Resemble that of parkinsonism but lacks rigidity& bradykinesia. Locomotion is slow, pt walks with very short,mincing, shuffling & some what irregular footsteps. Cause-- Normal Pressure Hydrocephalus ,- multi – infarct dementia,- normal elderly person.
Seen in extensive cerebral lesions – Frontal lobes,NPH, neoplasm, Binswanger’s disease, pick disease. Pt cannot carry out purposeful movement with legs& feet such as making circle etc. In rising, standing & walking there is difficulty ininitiating movement & automatic sequence ofcomponent movement is lost. Gait – slow, shuffling with short steps.
Greatest difficulty is in initiating walking, makingsmall, feeble, stepping movement with minimalforward progress, eventually unable to lift feetfrom floor, as if they were stuck or glued down –magnet gait, gait Ignition Failure,start hesitation.
More or less similar to gait apraxia. Characterized by slightly flexed posture, short,shuffling steps, inability to integrates & coordinatelower extremity movement to accomplish normalambulation. Disorder of frontopontocerebellar fibres.
• Occur with weakness of Hip girdle muscles,eg. myopathy, muscular dystrophy.• Hip abducter muscles vital in stabilizing pelviswhile walking.• Trendelenburg’s sign is abnormal drop of pelvison side of swing leg due to hip abducterweakness, when weakness is bilateral – exaggeratedpelvis swing that result in waddling gait.• Pt walk with broad base, exaggerated rotation ofpelvis, rolling or throwing hips from side to sidewith every step to shift weight of body.
Seen in older patient whohave no neurologicaldisease. but are uncertainof their balance & posturereflexes. Velocity slows, stepsshortens , base widens.