Regression of neuropsychological deficits in early-treated phenylketonurics during adolescence

Even early-treated phenylketonuric patients suffer from phenylalanine-associated (mild) neuropsychological impairment. To date it is still unclear whether patients' deficits show a progression on ageing. This unsolved question seems to be an important aspect in the still ongoing debate about how long and how strictly the patients should be maintained on diet. Twenty early-treated (20 +/- 10, 9-30 days) adolescent phenylketonurics (10 boys, 10 girls) and 20 healthy controls, matched for age, sex and IQ, were investigated twice at a mean ages of 11 and 14 years for their IQ (Culture Fair Intelligence Test-Scale 2; CFT-20), fine motor abilities (Motor Performance Task), sustained (Test d2) and selective attention (Stroop-Task). At the first test, examinations revealed significant blood phenylalanine-correlated neuropsychological deficits in PKU patients. In spite of raised blood phenylalanine concentrations during the following 3 years and significantly elevated concurrent blood phenylalanine concentrations, the repeated measurements revealed a significant decrease of patients' deficits compared to controls. Clinical-neurological status of patients and controls was normal at both test times. The results indicate a decreased vulnerability of PKU-patients with respect to their neuropsychological functioning against elevated blood phenylalanine levels on ageing.

Progressive peripheral and central sensory tract lesion in HIV-infected patients evidenced by evoked potentials (a three-year follow-up study)

OBJECTIVE

To investigate progression of peripheral and central sensory tract lesion and its correlation to immunological deterioration.

METHODS

Clinical and neurophysiological investigation (evoked potentials of the median and tibial nerve) and immunological parameters (CD4-cells, beta 2-microglobuline) were followed up in 160 patients (24 females, 136 males, HIV infection for 2.7 +/- 2.3 years, mv +/- 1 sd) up to four times over approximately 3 years regardless of disease stage and evidence of neurological symptoms. Recordings were done using needle electrodes over the Th12 and C7 spinous process and from the scalp (10/20 system) in the conventional manner. Statistical analysis was performed intraindividually and in comparison to normal laboratory values (n = 96).

RESULTS

All parameters deteriorated during the follow-up period. Statistical analysis showed significant differences between probands and patients for evoked potentials, but also a significant deterioration for evoked potentials after three years at the end of the follow-up study. A significant correlation between progressive impairment of evoked potentials and laboratory data was found.

CONCLUSION

HIV infection induces a progressive lesion of the ascending sensory tracts. The results indicate a peripheral neuropathy as well as a progressive lesion of the ascending central sensory tracts. Pathogenesis of polyneuropathy and of central sensory tract lesion is up to now conjectural. Laboratory investigations indicate a clear-cut correlation between immunological alterations induced by HIV infection and its neurologic manifestation on ascending sensory tracts.

[Routine electroencephalogram in follow-up of patients with HIV infections of different stages. A long-term study]

Electroencephalography (EEG) is a well-tolerated non-invasive method and is therefore well suited for repetitive examinations. We performed serial EEG's on 117 HIV patients without any clinical signs of secondary neuromanifestation in order to document electroencephalographic changes in the course of HIV infection. Clinical signs of HIV-associated encephalopathy presented 18 patients at the first examination and 23 at reexamination. EEGs were analyzed visually; there was a mean interval of 20.3 +/- 13.7 months between the first and the second examination. Significant slowing of background activity occurred in the course of the disease; the alpha rhythm decreased from 10.7 +/- 2.3 Hz to 10.0 +/- 2.4 Hz (P < 0.05) with an increase in amplitudes from 60.9 +/- 24.6 microV to 69.5 +/- 33.7 microV (p < 0.05). The percentage of spontaneous dysrhythmias also increased from 30.7% to 41.8% (P < 0.05); pathological findings provoked by hyperventilation increased from 13.6% to 18.2%. Foci occurred rarely and did not increase in frequency with time. CD4 cell counts decreased from 294.2 +/- 209.5/microliter to 188.7 +/- 208.3/microliter (P < 0.01). The results of this study indicate progressive CNS dysfunction with worsening of the immunostatus.

Progression of cerebral white matter abnormalities in early treated patients with phenylketonuria during adolescence

In this study of cranial MRI a group of 15 adolescents with classical phenylketonuria and permanent blood phenylalanine (phe) checks from infancy was investigated twice with an interval of three years in between. Cranial MRI revealed a progression of white matter abnormalities in patients with moderate and poor control of blood phe levels, however not in well controlled patients. Nevertheless results indicate an individual vulnerability of the brain against elevated phenylalanine levels in phenylketonurics.