Description
The patient was a middle aged male lying comfortably in
bed. He was tall but looked underweight.
On examination of his lower limbs, the two limbs were of
equal size and shape. There was no abnormality of the skin over the lower limbs.
There was generalised wasting of the muscles of the lower
limbs and there were fasiculations in the muscles.
The tone of the muscles was increased and they were
spastic.
There was a global decrease in power in the lower limbs
(grade 4).
The tendon reflexes were exaggerated, plantars were upgoing
and there was clonus at the patellar and ankle.
The heel shin test was acceptable for the degree of
weakness.
There was no sensory loss.
Gait was not examined.
Analysis
♥
The patient being underweight suggests a long-standing problem.
(ACES for PACES Page 66)
ª
Wasting of muscles suggests a problem involving the lower motor
neurone, muscle or disuse
(ACES for PACES Page
443)
¨
The presence of fasiculations narrows this down to disorders
affecting the lower motor neurone
(ACES for PACES Page
445)
§
Increased tone, spasticity, would suggest a problem affecting the
upper motor neurone (ACES
for PACES Page 449)
♥
Now we have to consider conditions that affect both the upper and
lower motor neurone in a generalised manner. This does not leave many
possibilities and motor neurone disease immediately comes to mind
(ACES for PACES Page
439)
ª
Decreased power adds further weight to this diagnosis.
(ACES for PACES Page
450)
¨
The exaggerated reflexes with clonus adds further weight to the
diagnosis of an upper motor neurone lesion (ACES
for PACES Page 453)
§
The absence of sensory signs excludes cord compression, which is
the most important differential diagnosis
(ACES for PACES Page
454)
Diagnosis
♥
Combination of lower motor neurone and upper motor neurone
lesions:
Motor neurone disease
See
KEYS to SUCCESS in Medicine page 471-473 page
