This document discusses motor symptoms such as weakness, paresis, and increased fatigability. It describes upper and lower motor neuron lesions, providing signs of each. Upper motor neuron lesions can be caused by cerebrovascular accidents, tumors, or demyelination. Lower motor neuron lesions involve anterior horn cells or the peripheral nerve, neuromuscular junction, or muscles. Types of weakness like hemiparesis and paraparesis are explained. The evaluation and etiology of hemiparesis is covered, noting it can be caused by cortical, cranial nerve, or high cervical spine lesions. The exam of the motor system and investigations for hemiparesis are also summarized.

1. Dr. Tahir Bashir
Assistant Professor
Medical Unit-4

2. Motor Symptoms
Weakness
Paresis
Plegia
Increased fatigability

3. Types of weakness
Upper motor neuron
Lower motor neuron

4. Evaluation of weakness

5. Upper Motor Neuron Lesion:Signs

6. Lower Motor Neuron Lesion:Signs

7. Upper Motor neuron lesion
Motor cortex
Descending motor axons
Causes:
 Cerebrovascular accident(Infarct/bleed)
 Tumour
 Demyelination

8. Lower motor neuron lesion
Anterior horn cellsAnterior horn cells
Poliomyelitis, Motor neuron disease
Peripheral nervePeripheral nerve
Peripheral neuropathy
 Neuromuscular junctionNeuromuscular junction
Myasthenia gravis
 MusclesMuscles
Muscular dystrophies

9. Hemiparesis
Paraparesis
Quadriparesis
Monoparesis
Distal weakness
Proximal weakness
Weakness in restricted area

10. 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

11. Un-crossed
Facial involvement
Hemiparesis

12. Crossed
Facial involved on same side or any other cranial
nerve involved (midbrain, Pons, Medulla)
Hemiparesis of opposite side.

13. Exam of Motor System

14. Etiology of Hemiparesis
Acute
Infarction
Hemorrhage
Trauma
Multiple sclerosis
Brain abscess
Sarcoidosis
Investigations
CT Brain
MRI Brain
MRI High Cervical Spine

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

16. Approach to UMN Weakness
Planter 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
in
brainstem)

17. THANKSTHANKS