Muscle morphometry in motor neuron disease.

It has previously been suggested that the pathological abnormalities seen in muscle biopsies from patients with motor neuron disease (MND) are of predictive value in relation to the rate of progression of the disease. In this study, quadriceps muscle biopsies from 19 patients with MND and 20 age matched controls were prepared for histochemistry and analysed morphometrically. Pathological features of denervation and reinnervation were observed in all MND patients although considerable variation between patients was noted. Motor neuron disease biopsies also showed increased connective tissue, an increased variation in fibre size, and a random fibre type distribution. Several of these abnormalities were more severe in female patients. Many of these 'abnormalities' were also frequent, albeit to a milder degree, in control biopsies and emphasize the need for age matched controls. The morphometric data was not related to the age of the patient, disease duration, type of MND or muscle strength, thus suggesting that the progression and severity of MND and its prognosis cannot be judged on the basis of quadriceps muscle pathology alone.