[Electroencephalogram evaluation of hyperphenylalaninemia patients on dietetic treatments].

OBJECTIVE

To explore the electroencephalographic changes of patients with hyperphenylalaninemia (HPA) after dietetic treatments.

METHODS

From July 2005 to February 2010, 34 HPA patients with abnormal electroencephalograms were recruited from China-Japan Friendship Hospital. Their electroencephalographic results and clinical features were compared before and after dietetic and antiepileptic treatments. There were 16 males and 18 females with an age range of 2 months to 8 years. All electroencephalographic results were abnormal. Among them, there were epileptic discharges (n = 17), atypical sharp-slow wave complex (n = 1) and slow wave background (n = 16). All patients received a low intake of phenylalanine at 13-50 mg·kg(-1)·d(-1). Twenty patients had antiepileptic drug therapy. Before and after treatment for 3 months, 6 months, 1 year and 2 years, blood phenylalanine concentration, electroencephalogram, convulsion and other clinical parameters were observed. Before and after 1 year treatment, the tests of developmental quotient (DQ) or intelligence quotient (IQ) were performed.

RESULTS

The phenylalanine concentrations of the same patient group decreased significantly after 3 months, 6 months, 1 and 2 years after dietetic treatment ( (0.51 ± 0.39) , (0.50 ± 0.29), (0.59 ± 0.42), (0.53 ± 0.27) vs (1.33 ± 0.64) mmol/L, all P = 0.000). Among 19 epileptic cases, 16 ceased after treatment. And 14 stayed convulsion-free within 3 months post-treatments, 2 cases had intermittent tonic-clonic seizures while there was 1 case of focal seizures. Fourteen cases withdrew antiepileptic medications or reduced their doses. After treatment, the electroencephalographic results became totally normal in 8 of the 19 epileptic cases. Electroencephalographic results improved in 5 cases versus pre-treatment. Spikes were controlled in 10 cases including 5 patients with hyperarrhythmia in the abnormal electroencephalographic group with epilepsy. Six cases continued abnormal electroencephalogram. In the abnormal electroencephalographic group without epilepsy (n = 15) , electroencephalograms were normal (n = 3), improved (n = 6) and continued mild abnormal waves (n = 2). However, there were 4 cases with deteriorated electroencephalogram and 3 of them showed spikes. DQ (IQ) was evaluated in 16 cases. And variable mental retardation was observed in all of them. After, year treatment, 7 cases were evaluated DQ (IQ), and their results showed improved (57 ± 16 vs 50 ± 16, t = -5.42, P = 0.002).

CONCLUSIONS

Etiological treatment for HPA patients is important for controlling epilepsy and improving brain function. And electroencephalogram is useful for monitoring brain functions and evaluating treatment outcomes.