INSTRUCTION
Perform a neurological examination of this patient's arms or legs.
SALIENT FEATURES
History
· Weakness of proximal muscles.
· Patient has difficulty in standing from the sitting position (getting up from chairs, getting off the commode) or difficulty in
combing her hair - elicit this history.
Examination
· Check the gait, looking for waddling gait (see p. 181).
· Look for an underlying cause:
- Diabetic amyotrophy (asymmetrical, usually in the lower limbs in non-insulin-dependent diabetes mellitus).
-Cushing's syndrome (characteristic facies, history of steroid ingestion; see
p. 385).
-Thyrotoxicosis (look for eye signs, goitre, rapid pulse, tremor). -Polymyositis (heliotropic rash, tender muscles). -Drug history
(alcohol, steroids, chloroquine). - Carcinomatous neuropathy. -Osteomalacia (bone pain).
- Hereditary muscular dystrophy.
DIAGNOSIS
This patient has weakness of the proximal muscles of the lower limbs (lesion) due to Cushing's syndrome (aetiology) and is severely
limited by the weakness (functional status).
QUESTIONS
What is Gowers' sign?
In severe proximal myopathy of the lower limbs, the patient on rising from the floor uses her hands to climb up herself. It has been
classically described in Duchenne muscular dystrophy.
What do you know about diabetic amyotrophy?
It is an asymmetrical motor polyneuropathy which presents with asymmetrical weak-ness and wasting of the proximal muscles of the
lower limbs and sometimes upper limbs, diminished or absent knee jerk and sensory loss in the thigh. It is usually accompanied by
severe pain in the thigh, often awakening the patient at night. The prognosis is good and most patients recover over months or years
with diabetic control.
ADVANCED-LEVEL QUESTIONS
What is the difference between type I and type 2 muscle fibres?
· Type 1 muscle fibres are high in myoglobin and oxidative enzymes and have many mitochondria. They perform tonic contraction
and are involved in weight-bearing and movements requiring sustained force. Chloroquine causes vacuolation of myocytes,
predominantly type 1 fibres.
· Type 2 muscle fibres are rich in glycolytic enzymes; they perform rapid phasic contractions and are involved in sudden
movements and in purposeful motion. In steroid myopathy the muscle fibre atrophy predominantly affects these fibres.
Sir W.R. Gowers (1845-1915), Professor of Medicine at University College Hospital, London, invented a haemoglobinometer,
personally illustrated an atlas of ophthalmology, and wrote a book on spinal cord diseases and a manual on the nervous system. He
also founded a society of medical stenographers.
Guillaume-Benjamin-Amand Duchenne (1806-1875) was first to describe Duchenne muscular dystrophy in 1868, when he described
13 cases of the disease; by 1870 he had seen about 40 cases