Patient with suspected myelopathy was admitted to the Family Health Hospital. A focussed examination to differentiate between an UMN (Upper motor neurone) and LMN (Lower motor neurone) lesion was carried out. Examination Findings: Inspection: No abnormality detected Tone: Increased Reflexes: Brisk Plantars: Upgoing bilaterally Clonus: Present bilaterally Power: Reduced – movement against gravity but not against resistance All 4 limbs affected equally. i. What scale is used for grading limb power? ii. What is this patient's grade of motor power? iii. Is this an UMN or LMN problem? What is the reason for your answer? iv. Where is the pathology likely to be located? What is the reason for your answer?

i. The scale used for grading limb power is the Medical Research Council (MRC) scale.

ii. Based on the description "movement against gravity but not against resistance", the patient's grade of motor power is Grade 3 on the MRC scale.

iii. This is an UMN (Upper Motor Neurone) problem.
The reasons are:

• Increased tone: UMN lesions typically cause spasticity (increased tone).
• Brisk reflexes: Hyperreflexia is characteristic of UMN lesions.
• Upgoing plantars bilaterally: This is a positive Babinski sign, a hallmark of UMN dysfunction.
• Clonus present bilaterally: Clonus is another sign of UMN pathology.

iv. The pathology is likely to be located in the cervical spinal cord.
The reasons are:

• The presence of UMN signs in all four limbs equally indicates a lesion affecting the descending motor pathways (corticospinal tracts) above the level where the innervation to the upper and lower limbs separates significantly.
• A lesion in the cervical spinal cord (myelopathy) can affect the UMN tracts supplying both the upper and lower limbs, leading to the observed bilateral UMN signs in all four limbs.