Localization in Neurology- 2

Specific lesions & syndromes

Lesion- CNS Upper motor neuron Weakness Disuse atrophy Spasticity Reflexes Extensor plantar NCV- normal No denervation

potentials in EMG

Lower motor neuron Weakness Wasting-marked & early Flaccidity Loss of reflexes Fasciculations NCV- abnormal Denervation potentials

in EMG

Lesion- brain UMN Spasticity UL-flexor, LL-extensor Paralysis of voluntary

movements No involuntary move. Exaggerated DTR Plantar-extensor

EPS Rigidity All-flexor>extensor Mildly decreased

voluntary movements Involuntary movements Normal DTR Plantar-flexor

Localization in spinal cord Uppermost sensory level

Pain over a vertebra Radicular pain Band-like sensation

Isolated flaccidity/atrophy/areflexia & distal UMN signs

Lesion- spinal cord Extramedullary Radicular pain Localised vertebral t’ness Brown-Sequard hemicord

syndrome Early UMN signs Ascending sensory symp. Sharp sensory level Marked sacral sensory loss Early CSF abnormalities

Intramedullary Poorly localised burning pain Dissociated loss of pain, with

spared joint position sense Late UMN signs Commom coexistence of

LMN+UMN signs Descending sensory symp. Sacral sparing Normal/minimally altered

CSF

Lesion- lower spinal cord Cauda equina Pain common, projected

to perineum/thigh LMN type paraparesis Asymmetric Saddle anaesthesia Late bladder & bowel

involvement

Conus medullaris Pain less prominent Absent anal reflex More symmetrical B/L saddle anesthesia Early bladder & bowel

involvement and impotence

MCA infarct Embolic Contralateral hemiplegia &/or

hemianaesthesia Dominant hemisphere- aphasia Non-dominant hemisphere-

agnosia & apraxia

Basilar artery infarct Mostly embolic Bilateral long tract signs-

sensory & motor With cranial nerve- V-VIII- symptoms With cerebellar dysfunction

Medullary syndromes Lateral Trigeminal sensory nucleus & spinothalamic tracts affected Causing I/L face & C/L body loss of pain & temperature

sensation Ataxia, nystagmus, vertigo, dysphagia, hoarseness Horner’s syndrome- ptosis, miosis, I/L anhidrosis

Medial Hypoglossal nerve, medullary pyramids & medial leminiscus

affected Causing I/L tongue deviation, C/L hemiplegia & C/L loss of

touch/position/vibration sensation

Bulbar palsy B/L LMN defect of IX-XII cranial nerves Dysphagia (liquid>solid), nasal regurgitation,

slurred speech Nasal speech, wasted tongue with fasciculation,

absent gag reflex

Pseudobulbar palsy- B/L UMN defect of IX-XII cranial nerves Dysphagia, dysarthria, emotional lability Slow indistinct speech, spastic tongue, brisk jaw jerk Frontal release signs

Craniovertebral junction anomaly Neck/shoulder pain Short, webbed neck with ROM Vertigo, drop attacks, syncope- due to

vertebrobasilar ischemia Upper cord compression- spastic paresis,

posterior column defects ± Lhermitte sign Brain compression- nystagmus, hoarseness,

dysarthria, dysphagia, ataxia

Spinal cord Transverse myelit is Upper sensory level for all sensations,

LMN signs at the level of lesion, flaccid paralysis (spinal shock)UMN signs distally, B/B involved

Anterior spinal artery syndrome Upper sensory level for pain/temperature,

sparing of posterior columns, UMN signs distally Brown-Sequard syndrome I/L spastic paralysis & loss of joint/position sense,

C/L loss of pain/temperature sensation

Motor neuron disease Selectively affect motor neurons, that

control voluntary muscle activity Types- Amyotrophic lateral sclerosis- UMN+LMN Primary lateral sclerosis- UMN Progressive muscular atrophy- LMN Bulbar palsy- bulbar LMN Pseudobulbar palsy- bulbar UMN

Inflammatory demyelinating polyneuropathy

Acute- AIDP Symmetric ascending weakness, cranial n. may be

involved, areflexia, myalgia With or without dysesthesias, loss of position sense

more common & severe than loss of pain/temp. Autonomic dysfunction- orthostatic hypotension

Chronic- CIDP- >8 weeks

In the end Neuromuscular junction- Symmetrical proximal muscle weakness,

with bulbar involvement Fatigable, variable Sensory, reflexes, bladder-bowel- normal Myopathy- Symmetrical proximal muscle weakness, bulbar

spared Progressive, waddling gait Sensory, reflexes, bladder-bowel- normal