|Classification and external resources|
It produces rapidly progressive weakness of tongue, face and pharyngeal muscles in a clinical pattern similar to myasthenia bulbar palsy. Neuromuscular transmission may be abnormal in these muscles because of rapid denervation and immature reinervation, and strength may improve with administration of cholinesterase inhibitors. Paralysis occurs secondary to degeneration of the motor neurons of the brain stem. It causes progressive bulbar paralysis due to involvement of motor neurons of the cranial nerve nuclei. The most frequent symptoms at onset of progressive bulbar paralysis of childhood has been a unilateral facial paralysis. It is followed in frequency by dysarthria due to facial weakness or by dysphagia. Palatal weakness and palpebral ptosis also have been reported in few patients. Both sexes can be affected.
Onset of first symptom has been reported between 1–12 years, with a mean age of onset at 8 years. Genetic expression is either an autosomal dominant or an autosomal recessive type. Clinical course can be divided into early (< 6 yrs age, predominance of respiratory symptoms) and late course (6–20 years of age, predominance of motor symptoms on superior limbs). Progression to involve other cranial nerve muscles occurs over a period of months or years. In the Gomez review facial nerve was affected in all cases while hypoglossal nerve was involved in all except one case. Other cranial nerves involved were vagus, trigeminal, spinal accessory nerve, abducent, occulomotor and glossopharyngeal in this order. Corticospinal tract signs were found in 2 of the 14 patients.
The disease may progress to patient's death in a period as short as 9 months or may have a slow evolution or may show plateaus. Post mortem examination of cases have found depletion of nerve cells in the nuclei of cranial nerves. The histologic alterations found in patient with Fazio-Londe disease were identical to those seen in Werdnig-Hoffman syndrome. Fazio-Londe disease, infantile progressive spinal muscular atrophy (Werdnig-Hoffman syndrome), Juvenile progressive spinal muscular atrophy (Kugelberg-Welander disease), Brown-Vialetto-Van Laere syndrome (BVVL) and the juvenile type of slowly progressive bulbar palsy, all have been considered variants of chronic progressive disease of lower motor neurons.
To date, there is no test of confirmation for Fazio-Londe disease, although researchers are currently searching to isolate the responsible gene.
Berger, in 1876, first reported a case of 12-year-old child with progressive bulbar paralysis. From India, Reddy and Murthy first reported a Fazio-Londe disease case in 1982. Until now only 31 cases have been published in the literature.