Dr. Tahir BashirAssistant Professor

Medical Unit-4

Motor SymptomsWeakness

ParesisPlegia

Increased fatigability

Types of weaknessUpper motor neuronLower motor neuron

Evaluation of weakness

Upper Motor Neuron Lesion:Signs

Lower Motor Neuron Lesion:Signs

Upper Motor neuron lesionMotor cortexDescending motor axons

Causes: Cerebrovascular accident(Infarct/bleed) Tumour Demyelination

Lower motor neuron lesionAnterior horn cellsAnterior horn cells Poliomyelitis, Motor neuron disease

Peripheral nervePeripheral nerve Peripheral neuropathy

Neuromuscular junctionNeuromuscular junction Myasthenia gravis

MusclesMuscles Muscular dystrophies

HemiparesisParaparesisQuadriparesisMonoparesisDistal weaknessProximal weaknessWeakness in restricted area

HemiparesisHemiparesis• Cortical

– Language– Sensory disturbance– Apraxia– Seizures– Visuospatial integration disorder– Homonymous field defects

• Cranial nerve– Crossed– Uncrossed

• High cervical spine– No cranial nerves involved – Face is not involved– Sensory disturbance– Ipsilateral proprioception– Control pain and temperature– Brown sequard

Un-crossedFacial involvementHemiparesis

CrossedFacial involved on same side or any other

cranial nerve involved (midbrain, Pons, Medulla)

Hemiparesis of opposite side.

Exam of Motor System

Etiology of HemiparesisAcute

Infarction Hemorrhage TraumaMultiple sclerosisBrain abscessSarcoidosis

InvestigationsCT BrainMRI BrainMRI High Cervical Spine

ParaparesisParaparesis• Brain Parasagittal Lesion / hydrocephalus• Spinal cord at or below upper thoracic• Anterior Horn Cells• Cauda Equina Syndrome (Hip flexion / sensation over

anterolateralthigh spared)

• Peripheral neuropathy GB Syndrome• Myopathy

Episodic:– Multiple sclerosis– Vascular malformation of spinal cord

Acute– Cord compression– Abcess– Spinal cord infarction – AV fistula / vascular anomaly– Transverse myelitis– Associated cerebral ischemia– Parasagital sinus / cortical Venous thrombosis– Acute hydrocephalus– Trauma

Approach to UMN WeaknessPlanter Upgoing

Yes No

Mono plegia LMN Lesion

Yes No

Fits Hemiplegia

Yes NO Yes No

(Lesion in Motor cortex) (Corona Radiata) Un crossed crossed Paraplegia

(internal capsule) Crossed

LMN VII N other cranial N

(Lesion

inbrainstem)

THANKSTHANKS