• MYOMETRY
• CLINICAL NEUROLOGY
• Upper motor neurone lesion
• pyramidal weakness

The signs associated with an upper motor neurone syndrome vary considerably between text books. Often included are loss of dexterous, rapid and fractionated voluntary movements, variation of movement with mode of activation (prime mover, synergist, antagonist), weakness, various postural signs (eg, pronator drift), time-dependent tonal and tendon reflex changes and the extensor plantar response. Russell Brain’s first edition of Diseases of the Nervous System (1933, pp 6-8) refers to movements of flexion being stronger than extension in the upper limb and extension movements stronger than flexion in the lower limb as one negative feature of a unilateral pyramidal (internal capsular) lesion, albeit attributing this ‘probably’ to the distribution of hypertonia. However, this pattern of ‘pyramidal weakness’ (also including shoulder abduction) has since been emphasised in many text books as being characteristic of an upper motor neurone lesion.

Early in my consultant career, I saw a man with acute pain in the low and mid back and weakness in both legs. He could barely stand, tone was normal and he had weakness of hip flexion more than …