CLINICAL ANALYSIS OF PKU WITH WEST SYNDROME

Zhou Z-S, Yu W-M, Zheng C-N, Ariizumi M-M

Department of Pediatrics China-Japan friendship hospital, Beijing, China

 

Objective: To explore the etiology of phenylketonuria (PKU) patients with West syndrome (WS) by clinical analysis.

Subjects and Methods: Of 62 PKU patients with WS (41males, 21females), the age at WS onset ranged mainly from 4 to 18 months and PKU diagnostic ages of the first time were between 4 months and 7 years. The serum level of phenylalanine (PHE) indicated above 20mg/dl in all patients. All the patients received diet therapy and EEG examination. MRI was undergone and brain maturation was observed with staudt’s method in 15 patients.

Result: 1. PKU patients had a high incidence of WS, accounting for 12.2% of PKU patients experienced in our hospital (62/503). In respect to the starting age of the treatment, 3 months suffered from WS. In contrast, 12.2%PKU patients older than 3 months at onset of the treatment got WS. 2. At the beginning of seizure, flexor type appeared rather common compared to other 3 types containing mixed type, extensor type and atypical seizure. 3. PKU-WS patients had delayed myelination (100%) mainly in brain lobes and corpus callsom. Meanwhile, their T2-weighted images demonstrated the abnormal high signal intensity in the peripheral region around anterior and posterior horns and the central of both lateral ventricles. With reduction of serum PHE level during diet therapy, delayed myelination and abnormal high T2-sign on MRI image could recover gradually. By comparison, the delayed myelination was fond in only 62% of PKU patients without WS. 4. The seizure frequency was decreased when PHE concentration was diminished under 4 mg/dl gradually. Once combined with anti-epileptic treatment (valproate and/or nitrazepam), the patients mostly ceased seizure in 3 to 9 months.

Conclusion: 1. PKU patients have a high occurrence of WS. The occurrence of WS in PKU patients is closely related to not only PHE serum level but also to the age of starting treatment. 2. MRI images of PKU-WS patients showed a high incidence of delayed myelination and abnormal high T2-sign. With reduction of PHE in blood, delayed myelination, abnormal high T2-sign and the frequency of seizure decreased. 3. Early diagnosis and dietary treatment of PKU is importent for preventing and controlling seizure PKU-WS.

 
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