Table 1.
Clinical Features
| Affected Subject | S1 | S2 | S3 | S4 | S5 | S06 |
|---|---|---|---|---|---|---|
| Gender | female | female | male | male | male | female |
| Year of birth | 1987 | 1998 | 1997 | 2000 | 2007 | 2009 |
| Siblings (affected / unaffected / otherwise affected) | 1 / 0 / 0 | 1 / 0 / 0 | 0 / 1 / 0 | 0 / 1 / 0 | 0 / 8 / 0 | 0 / 1 / 0 |
| Consanguinity parents | − | − | + | + | + | − |
| Pregnancy, delivery, neonatal period | normal | normal | normal | normal | normal | normal |
| Initial motor & cognitive development | normal | normal | normal | normal | mildly delayed | normal |
| Single Episode of Regression | ||||||
| Age at presentation (years) | 2.5 | never developed neurological signs | 3 | 5 | 5 | 2 |
| Signs at presentation | L-hemiparesis, somnolence, irritability, loss of ambulation | NA | delayed speech, gait difficulties | gait difficulties | dysarthria and gait difficulties | frequent falls and leg weakness |
| Preceding event | recurrent vomiting and poor growth | NA | NA | NA | febrile illness | febrile illness |
| Signs of regression | severe spastic tetraparesis, lowered consciousness | NA | spastic tetraparesis L > R | spastic tetraparesis, ataxia and sensorimotor polyneuropathy with loss of unsupported walking | spastic tetraparesis, ataxia and sensorimotor polyneuropathy with loss of unsupported walking | spastic tetraparesis and sensorimotor polyneuropathy with loss of ambulation; gastrostomy due to swallowing defect |
| Treatment | temporary improvement on steroids; riboflavin, coenzyme Q10, thiamine and vitamin C | coenzyme Q10, carnitine and vitamin C | none | none | none | riboflavin, coenzyme Q10 |
| Duration of regression | 2 months | NA | 2 years | 2–3 months | 2–3 months | 5 months |
| Further regressions | seizures at age 4, controlled with carbamazepine; no further regression | NA | a somnolence episode with generalized seizure at age 5; 3 seizures during follow-up of 11 years; no further regression | no further regression | no further regression | no further regression |
| Outcome | ||||||
| Age (years) | 26 | 14 | 16 | 13 | 6.5 | 4 |
| Motor function | wheelchair-bound | normal | moderate spastic tetraparesis L > R; wheelchair-bound | walks, mild signs of spasticity, ataxia, and peripheral neuropathy | walks, mild signs of spasticity, ataxia, and peripheral neuropathy | walks, spastic gait |
| Cognitive level | decreased | normal | decreased | slightly decreased | normal | normal |
| Speech and language | single words, marked dysarthria | normal | dysarthria | normal | normal | normal |