Progressive bulbar paralysis in childhood: a case report

Brown-Vialetto-Van Laere syndrome: clinical and neuroradiological findings of a genetically proven patient

The Brown-Vialetto-Van Laere syndrome (BVVLS) is a rare neurological disorder characterized by progressive pontobulbar palsy, sensorineural deafness and mixed spinal and upper motor neuropathy. Mutations in the C20orf54 gene have been linked to the disease and recently we reported the first Italian case of a BVVLS family with an intriguing C20orf54 genotype. However, the pathomechanisms underlying BVVLS are still unknown. Here we present the particular disease course with partial response to immunosuppressive therapy of our BVVLS patient for whom we hypothesize that dysimmune factors may have played a role in disease physiopathology.

The Brown-Vialetto-Van Laere and Fazio Londe syndrome revisited: natural history, genetics, treatment and future perspectives

The Brown-Vialetto-Van Laere syndrome is a rare neurological disorder which may present at all ages with sensorineural deafness, bulbar palsy and respiratory compromise. Fazio-Londe syndrome is considered to be the same disease entity. Recently it was demonstrated that in some patients the disease is caused by mutations in the SLC52A3 gene which encodes the intestinal (hRFT2) riboflavin transporter. In these patients riboflavin deficiency is the cause of the BVVL/FL syndrome and supplementation of riboflavin proved a life saving treatment. Mutations in the SLC52A2 gene and the SLC52A1 (GPR172B) gene, coding for human riboflavin transporters hRFT3 and hRFT1 have been associated with the BVVL syndrome as well. We performed a review of the literature, with emphasis on the natural history and the effects of treatment in these patients. A total of 35 publications were traced reporting on the clinical presentation of 74 patients who presented before age 18. The most prevalent symptoms were bulbar palsy, hearing loss, facial weakness and respiratory compromise. Death was reported in 28 of the 61 untreated patients, with a very low survival in patients presenting before age 4. All 13 patients who were treated with riboflavin survived, with a strong clinical improvement after days to months of treatment in eight patients. Three patients demonstrated a stable clinical course and treatment was stopped early in two patients. Abnormalities in plasma flavin levels and/or plasma acylcarnitine profiles were observed in some but not in all patients, and also patients with normal plasma flavin levels and acylcarnitine profiles demonstrated a striking clinical improvement on riboflavin supplementation. It is now clear that proper diagnosis requires mutation analysis of all three transporter genes and treatment should be started immediately without first awaiting results of molecular analysis. Clinical improvement may be rapid or gradual over a period of more than 12 months.

Progressive bulbur paralysis (Fazio-Londe disease)

Progressive bulbar paralysis of childhood is characterised by progressive paralysis of muscles innervated by cranial nerves. The authors report a case of progressive bulbar paralysis of childhood in a 12-year-old child. Child was admitted with the complaints of drooping of eyelids, difficulty in swallowing and hoarse voice. She had involvement of III, VII, IX, X, XI and XII cranial nerves and the corticospinal tracts. Electromyography revealed spontaneous activity in the form of fasciculations, giant motor unit potential and discrete recruitment of motor neurons suggestive of denervation pattern. Hearing assessment was normal. Muscle biopsy was also suggestive of neurogenic atrophy.

Infantile progressive bulbar palsy with deafness

A 12-month-old boy with progressive cranial nerve palsies followed by ventilatory failure demanding artificial ventilation, generalized muscle weakness, and rapid progression to death at the age of 21 months is described. The patient had normal early development and also apparently normal hearing at presentation of illness but, after 6 months of the onset of the disease, hearing loss was documented by brainstem auditory evoked potentials (BAEP). Although the initial clinical and laboratory findings of this infant could fit with the diagnosis of progressive childhood bulbar palsy or Fazio-Londe (FL) disease, the subsequent appearance of hearing loss suggests that this patient represents a case of progressive bulbar palsy with perceptive deafness or Brown-Vialetto-Van Laere (BVVL) syndrome. To our knowledge, this case of BVVL syndrome with severe clinical features and rapid deterioration leading to death is the youngest one reported in the literature. Furthermore, this case emphasizes the need for repeated auditory examinations, including the performance of BAEP in all cases, especially infants and young children with progressive bulbar palsy.