APPROACH TO A
PATIENT WITH CNS
DR M SHOAIB SHAFI
MAIN PRESENTING COMPLAINTS
Headache, backache or neck pain
Fits ,faints or funny turns
Dizziness or vertigo
Disturbance of vision, hearing or smell
Disturbance of memory, sphincter control,
sleep, speech, language or gait
Disorders of movement
abnormal involuntary movements
Acute confusional state
Coma and brain death
Problem with brainstem function
APPROACH TO DIAGNOSIS
It involves two questions:
Where is the lesion?
What is its etiology?
Where is the lesion?
1) Is the lesion :
Single,multiple or is it a diffuse process
Restricted to CNS or part of systemic illness
2) Do the findings combine to form a
recognizable clinical syndrome eg parkinsonism
Onset of illness & its course
Comorbation of history by attendants
Drug use, abuse & toxin exposure
Formulating an impression of the patient
HANDS ( CLUBBING,SPLINTER HGES)
FACE (FEATURES OF C.T DISORDER,EYE,SINUSES)
CENTRAL NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM
HIGHER MENTAL FUCTION
Time- knows month or year
Place- has general knowledge of where they are
Person- knows own name, able to name relatives or friend
Memory- capability for early and recent recall
Sense of position and vibration
Two point discrimination
BOTH UPPER & LOWER LIMBS
Bulk of muscles
Tone of muscle
Power of muscles
Coordination of movement
Tin-pot dictators have ravaged Asia, Latin America &
Africa. They are the worst tyrants of post-colonial period.
They have destroyed time-honored institutions & treated
their people like animals. They have caused internal
divisions &external confusion. The dictator is one animal
who needs to be caged. He betrays his profession & his
constitution. Not a single one of them has made a
moments contribution to history.
A 45yrs old lady is brought to ER with c/o sudden weakness of
right half of body. O/E
BP = 180/110 mmHg
Pulse = 68/min
CNS: GCS 7/15
Power decreased on right
Tone increased on right
Right plantar upgoing
Right facial nerve palsy (UMN type)
Explain the nature of lesion.
A 56yrs old gentleman with h/o uncontrolled
hypertension presents in ER with sudden onset
of weakness of left arm.
Where is the lesion in brain?
Two cerebral hemispheres
All the right handed persons and most of left
handed persons have left hemisphere as the
Dominant hemisphere controls the speech.
Spinal cord begins at the end of medulla oblongata and
extends upto lumbar vertebra 2 or 3 in adults.
Lower tapering part is called conus medularis and the
lowermost bundle of nerve fibres is called cauda equina.
It contains all the ascending and descending fibres.
Lesion here can cause hemiplegia, paraplegia or
Main arteries are:
Internal carotid arteries
Anterior cerebral arteries
Middle cerebral arteries
Posterior cerebral arteries
These form a circle called CIRCLE OF WILLIS
Areas of supply
MCA supplies lateral surface of frontal, parietal
& temporal lobe ie most of the motor & sensory
cortex except which lies on medial side and
ACA supplies medial side of brain.
PCA supplies the occipital lobe.
Cerebellum (for coordination)
Neurons in precentral gyrus
Posterior limb of internal capsule
Cerebral peduncle in pons
Decussation of fibres occur in pyramids of MO
and then descend as lateral corticospinal tracts.
APPROACH TO WEAKNESS
First determine whether its:
Weakness of all 4 limbs
Weakness all 4
Cervical spinal cord
Or bilateral brainstem
Distal sensory loss
No sensory loss
Weakness in both
Upper motor neuron
Spinal cord, thoracic spine or above
Lesion in brainstem
Single named nerve yes
Multiple named nerves yes
A 50yrs old male suddenly develops weakness of
left half of body. O/E there is weak left arm &
leg with increased tone & upgoing plantar. There
is sensory loss also.3 days later patient starts
complaining of agonizing pain down the left leg.
Patient says that he feels like as his flesh is being
torn away from bones.
What is the lesion and where is the lesion?
A 46yrs old male is brought to OPD with
c/o sudden inability to walk & to hold the
objects. O/E pt is having right nystagmus.
There is dysarthria & past pointing on right.
When asked to walk, patient sways to right.
Where is the lesion in CNS?
It is concerned with joint position sense,
vibration and touch
Axons proceed in the posterior column to dorsal
column nuclei in medulla
Second order neurons decussate and ascend in
medial lemniscus to thalamus
From thalamus fibres relay in parietal sensory
Lateral spinothalamic tract
It is concerned with pain and temperature
Fibres synapse in posterior horns and decussate
in the center of cord
Later they pass in lateral column as
spinothalamic tract and join medial leminiscus to
Symptoms of Sensory disturbances
Being unable to feel feet on the floor
Unable to judge temperature of bath water
Pins and needle sensations
Paraesthesias and pain in nerve root region of
Patterns of Sensory loss
Single nerve lesion e.g., median n. lesion
as in cervical or lumbar disc protrusion
Peripheral nerve lesion
e.g., neuralgias, glove and stocking sensory loss
Brain stem lesions:
loss of pain and temperature on ipsilateral half of face
and opposite half of body (e.g. lateral medullary
Patterns of Sensory loss
hemisensory loss of all modalities and severe
deep seated burning pain
(Dejerine roussy syndrome )
Cortical lesion (parietal lobe )
Hemisensory loss of all modalities
Spinal cord lesions
Gulzar bibi, 65 yr old lady presented via opd
with c/o gradual weakness of both the legs for
last 2months associated with urinary and fecal
incontinence. There is also a c/o tingling and
burning sensation in the legs.
An old lady lying in bed, conscious.
No abnormality on inspection
Power 0/5 in both the legs
Tone decreased in both the legs
Plantars bilaterally upgoing
Sensory level at T6
what is the investigation of choice?
MRI spine showed degenerative spondylitis at
mid and lower thoracic spine,most evident at
T8 & T9 causing cord compression.
Mr Fazal kareem, an 80yr old gentleman
presented in ER with c/o weakness of legs,
constipation & urinary retention. Patient
referred to surgical unit as a case of intestinal
obstruction and urinary retention. Later no
surgical abnormality detected. Medical
BULK equal bilaterally
TONE increased in both the legs
POWER 2/5 in both legs
SENSORY LEVEL T4
Miss maryam, 16 yr old presented in OPD with
c/o progressively increasing difficulty in
3/5 in both legs
Ankle & knee clonus positive
Patient had pulmonary TB 3yrs back, took
ATT for 2months.
MRI spine showed two soft tissue density
masses in thoracic spine causing cord
Histopathology of the mass showed
features consistent with the diagnosis of
A 30 yrs man is brought to ER after an RTA causing
injury to spine. O/E:
Power 0/5 in the legs
Tone decreased in both legs
Complete absence of all sensations below the umbilicus
A 40 yrs old male, victim of earthquake with spinal injury
is admitted in the ward. Examination of legs shows:
Power 0/5 in left leg
Tone increased in left leg
Left plantar upgoing
Reflexes brisk on left side
Absent joint position & vibration sense on left
Absent pain & temperature sensation on right
What is the pathology?
A 57 yrs old man is brought to ER with c/o sudden
inability to walk. O/E power reduced in both legs with
upgoing plantars. There is loss of pain & temperature
sensation in both legs but joint position sense is intact.
What is your diagnosis?
A 48 yrs old male is brought to ER with c/o weakness
of all the four limbs over a period of 1year. However
there is no incontinence. Thre is also dysphagia.
Examination reveals UMN quadriplegia with visible
fasciculations over the tongue. Uvula deviates to left
when 10th nerve is examined.
Where is the lesion & what is the pathology?
A 42 yrs old lady comes in OPD with c/o numbness of
both the hands and difficulty in holding the objects.
O/E there is absent pain & temperature sensation over
the hands and forearms. Sensory loss is dissociated.
Sense of vibration and joint position sense is intact.
There is weakness of small muscles of hands.
What is your impression?
A 65 yrs old gentleman is brought to OPD with c/o progressively
increasing generalised weakness, anorexia, SOB & easy
bruisability. There is previous h/o partial gastrectomy due to
unknown reason. O/E:
An elderly gentleman with marked pallor, bilateral pitttting edema
feet & bruises over the arms and legs.
Hb = 5.7 g/dl
Serum albumin = 2.7 g/dl
= 22sec/ 14 sec
What is your diagnosis & management plan?
3/5 in legs
REFLEXES : absent ankle reflex on both sides
Absent sensations upto knees
Bilateral loss of all modalities below the level of
Contralateral loss of pain and temperature
Ipsilateral loss of touch and pressure
Below the level of lesion
Brown sequard syndrome
Contralateral loss of pain and
Temp with preservation of
Spinal cord lesions
Posterior column loss
Anterior spinal artery syndrome:
Involvement of lateral spinothalamic tract with
preservation of dorsal column
Contralateral hemiplegia with hemisensory loss
Left hemisphere; dominant:
Cortical sensory loss
Inattention, denial, constructional apraxia,
dressing apraxia, spatial disorientation
Contralateral weakness mostly monoplegia
Sensory loss according to area involved
Dense contralateral hemiplegia and sensory loss
Face, arm and leg equally affected
Third and fourth cranial nerves
Descending corticospinal and corticobulbar
Clinical syndromes associated with
Weber´s syndrome: Contralateral hemiplegia and
ipsilateral third nerve lesion
Benedikt´s syndrome: third nerve palsy with
involuntary movements of opposite limbs (red
Involvement of reticular formation; patient makes
no voluntary movements except that of eyes
Lesions in pons
It contains 5th, 6th,7th & 8th cranial nerve nuclei.
Lateralized lesion in pons causes ipsilateral CN
involvement with crossed paralysis or sensory loss as in
Millard Gubler syndrome. (6th and 7th nerve palsy)
Central pontine lesion may cause coma, hyperthermia
& pinpoint pupils.
Locked in syndrome: only eye movement is possible. Pt
is able to communicate via eye signals.
Lesions in medulla
Medial medullary syndrome:
Weakness and loss of postural sense in limbs on
side oposite to lesion with ipsilateral paralysis of
Hiccups and vomiting
Ipsilateral horners syndrome
Ipsilateral cerebellar lesion
Ipsilateral sensory loss in face
Contralateral loss of pain and temperature in limbs
Ninth and tenth cranial nerve palsies
Pyramidal tract is not involved
Multiple Cranial nerve abnormalities
IIIrd nerve palsy yes
VI and/ or VII
XII ± IX and XI
VII and VIII
Combined III, VIth yes
X and XI
Middle cerebral artery
It constitutes 2/3 of all cerebral infarcts
Contralateral hemiparesis and sensory loss, arm
and face most affected
Expressive aphasia(dominant hemisphere)
Anosogonosia and spatial disorientation (nondominant)
Contralateral inferior quadrantanopia
Anterior cerebral artery
It constitutes two percent of all infarcts
Contralateral hemiparesis and sensory loss,
worse in leg
Incontinence of urine
Loss of verbal fluency but preserved ability to
Posterior cerebral artery
As it supplies occipital lobe, so lesion causes
visual field defects, contralateral homonymous
Mono or hemiplegia
Loss of cortical sensations
Contralateral homonymous lower quadrantanopia
Dominant lobe involvement causes acalculia, agraphia,
finger agnosia, right left disorientation----Gerstmann
Non-dominant lobe involvement causes sensory and
visual inattention, spatial neglect, apraxia, anosogonosia
Auditory or olfactory hallucinations
Auditory or visual illusions
Contralateral homonymous quadrantanopia
déjà vu phenomenon
Homonymous hemianopia with macular sparing