Bonnie E. Levin

Cognitive impairments associated with early Parkinson's disease

We administered a battery of cognitive tests to 41 recently diagnosed Parkinson patients and 41 controls to assess the early neuropsychological changes associated with Parkinsons disease (PD). Parkinson subjects did as well as controls on tasks assessing attention and select language and visuospatial measures. However, PD subjects did significantly worse on embedded figures, facial recognition, proverbs, and verbal and figural memory measures, and made more perseverative responses on a set shifting task. A discriminant function of measures of proverbs, embedded figures, and memory accounted for 22% of the variance between groups. These data suggest that the cognitive changes in early PD are more pervasive than originally described and may reflect the onset of a more widespread pathologic process.

Visuospatial impairment in Parkinson's disease

We explored the nature of the visuospatial deficit in Parkinsons disease (PD) and its progression as a function of disease duration. We compared the performance of 183 patients with idiopathic PD and 90 control subjects matched for age and education on six visuospatial measures. We divided patients into three groups according to the disease duration: early (1 to 4 years), middle (5 to 10 years), and advanced (> 10 years). Performance deteriorated in five of the six visuospatial measures, as a function of disease duration. However, the pattern of visuospatial decline depended on whether dementia was present. The results were not influenced by age or anticholinergic medication. These findings support the presence of visuospatial deficits in PD patients, with a changing pattern of impairment related to dementia and progression of the disease.

Temporal lobectomy in early childhood

Summary: Children with medically resistant temporal lobe seizures that persist into adolescence often experience psychosocial deterioration and medical morbidity. It is therefore especially important to evaluate the contribution of surgical therapy in preadolescent children. We describe our experience with temporal lobectomy in 16 children <12 years (mean age 7 years) who had intractable seizures of temporal lobe origin. Structural lesions were identified on neuroimaging studies in 11 patients. In all patients, the standard anterior temporal lobectomy was tailored according to the extent of the lesion and epileptogenic field. At follow‐up, 11 children were seizure‐free, three were 90% improved, one was 50% improved, and one was unchanged. Neuropathological abnormalities were identified in virtually all children. Prenatally acquired abnormalities of neurogenesis were the most common, whereas mesial temporal sclerosis was found in only two children. We conclude that tailored temporal lobectomy in the first decade of life is highly beneficial in carefully selected children with medically refractory seizures.

Parkinson's disease and depression: psychometric properties of the Beck Depression Inventory

Although the Beck Depression Inventory (BDI) is one of the most frequently employed measures of depression in Parkinsons disease, the somatic items included in the scale raise questions about its ability to differentiate depression from manifestations of the disease. The internal consistency and validity of the BDI as a measure of depression in a sample of 119 Parkinsons disease patients and 76 controls were studied. Results from an item analysis suggested that depression in Parkinsons disease patients is not a somatic artifact. Internal consistency reliability within the Parkinsons disease group was high. The factorial validity of the BDI was confirmed in both Parkinsons disease and control subjects. The results also indicated that Parkinsonian symptoms of depression can be measured separately from symptoms of the disease. These data suggest that the BDI including the somatic items is a reliable and valid measure of depression in Parkinsons disease and control subjects.

Cerebrospinal fluid dopamine in HIV-1 infection

BackgroundIncreasing evidence suggests significant involvement of the basal ganglia in patients with HIV-1 infection. ObjectiveTo study the effect of HIV-1 infection on cerebrospinal fluid (CSF) dopamine levels. DesignCSF dopamine levels were measured by high-performance liquid chromatography. SettingA university-based outpatient clinic in south Florida involved in clinical AIDS research. SubjectsTwenty-two subjects were enrolled in a prospective, longitudinal study of the neurological complications of AIDS. Five subjects were HIV-seronegative, but at risk for HIV-1 infection, 11 were HIV-1-seropositive without neurological disease and six had HIV-1-related neurological disease. ResultsThe CSF dopamine mean values were significantly lower in the HIV-1-seropositive group with (P< 0.0001) or without (P < 0.0001) neurological disease than in the HIV-seronegative group. There was a very strong correlation between CD4 lymphocyte counts and CSF dopamine levels (P=0.004) in the neurologically symptomatic group (P= 0.0008), but not in the other two groups. ConclusionHIV-1 infection appears to have an effect on the central nervous system dopaminergic systems, as reflected in levels of CSF dopamine.

Transcranial Doppler assessment of cerebral flow velocity during cognitive tasks.

Background and Purpose The purpose of this study was to assess the ability of transcranial Doppler ultrasonography to detect selective circulatory changes during cognitive activity. Methods We measured cerebral artery flow velocity in 21 normal volunteers by transcranial Doppler ultrasonography during rest followed by cerebral activation. Mean and peak systolic flow velocities of the anterior, middle, and posterior cerebral arteries were measured during the performance of a commercial video game. We also measured flow velocity of the anterior cerebral arteries in 18 subjects during a mental arithmetic task. Serial measurements of the right and left sides were made with a headband with two probes. Results We observed a global increase in the flow velocity above baseline measurements during task performance. During the video game, both middle cerebral arteries (f=2.6,p=0.02 for the left; f=33,p=0.004 for the right) and the left posterior cerebral artery (l=2.2, p=0.004) had selective increase in mean flow velocity compared with the ipsilateral anterior cerebral artery. This selective activation was most prominent in the right middle cerebral artery, which had a greater degree of activation than the right posterior cerebral artery (f=2.8, p=0.013). We did not observe a statistically significant difference between the right and left middle cerebral arteries, but there was a trend toward a greater activation on the right for both the mean velocity (t=1.7, p=0.098) and the peak velocity (f=1.9,p=0.079). Conclusions Our preliminary investigation suggests that this noninvasive technique has the potential to correlate selective cerebral artery flow dynamics with cognitive activity.

Contrast sensitivity in dyslexia

Contrast sensitivity was determined for dyslexic and normal readers. When testing with temporally ramped (i.e. stimuli with gradual temporal onsets and offsets) gratings of 0.6, 4.0, and 12.0 cycles/deg, we found no difference in contrast sensitivity between dyslexic readers and controls. Using 12.0 cycles/deg gratings with transient (i.e. abrupt) onsets and offsets, we found that dyslexic individuals had, compared to controls, markedly inferior contrast sensitivity at the shortest stimulus durations (i.e. 17, 34, and 102 ms). This deficit may reflect more sluggish temporal summation. There was no difference in sensitivity to 0.6 cycles/deg gratings with transient onsets and offsets. Under these conditions, the two groups showed a consistent and equal increase in sensitivity relative to the ramped baseline condition at 0.6 cycles/deg at the longer stimulus durations. This demonstrates that dyslexic readers have no deficit in their ability to detect stimulus transients, a finding which appears to be inconsistent with a transient system deficit. That detection of the low-frequency stimuli was mediated by the transient system is further indicated by the fact that these stimuli were more susceptible to forward masking than were the high-frequency stimuli. The effects of masking of both high and low spatial-frequency stimuli were about equal for dyslexic readers and controls. This is not in agreement with the transient system deficit theory, according to which one would expect there to be less masking of high spatial-frequency stimuli in the case of dyslexic readers.

A recommended scale for cognitive screening in clinical trials of Parkinson's disease

Cognitive impairment is common in Parkinsons disease (PD). There is a critical need for a brief, standard cognitive screening measure for use in PD trials whose primary focus is not on cognition. The Parkinson Study Group (PSG) Cognitive/Psychiatric Working Group formed a Task Force to make recommendations for a cognitive scale that could screen for dementia and mild cognitive impairment in clinical trials of PD where cognition is not the primary outcome. This Task Force conducted a systematic literature search for cognitive assessments previously used in a PD population. Scales were then evaluated for their appropriateness to screen for cognitive deficits in clinical trials, including brief administration time (<15 minutes), assessment of the major cognitive domains, and potential to detect subtle cognitive impairment in PD. Five scales of global cognition met the predetermined screening criteria and were considered for review. Based on the Task Forces evaluation criteria the Montreal Cognitive Assessment (MoCA), appeared to be the most suitable measure. This Task Force recommends consideration of the MoCA as a minimum cognitive screening measure in clinical trials of PD where cognitive performance is not the primary outcome measure. The MoCA still requires further study of its diagnostic utility in PD populations but appears to be the most appropriate measure among the currently available brief cognitive assessments. Widespread adoption of a single instrument such as the MoCA in clinical trials can improve comparability between research studies on PD.

Differential effects of aging on two verbal fluency tasks

The effect of age on verbal fluency was studied in 84 healthy volunteers, ages 45 to 91 years, who performed letter-fluency and semantic-fluency tasks. Older subjects (75 to 91 yr.) performed as well as younger (50 to 64 yr.) on letter fluency but did significantly worse on semantic category fluency. This pattern is similar to that observed in Alzheimer-type dementia.

Childhood obsessive-compulsive disorder and cingulate epilepsy

There are no reports of an association between obsessive-compulsive disorder and cingulate epilepsy in childhood. We report the behavioral, cognitive, and EEG findings in a young girl with medically resistant seizures and severe obsessive-compulsive symptomatology. Her scalp EEG and neuropsychological test scores suggested right frontal lobe dysfunction. The intractability of her seizures and progressive intellectual and psychosocial deterioration prompted evaluation for excisional surgery. Intracranial EEG recording demonstrated a focal seizure origin in the right anterior cingulate gyrus. Cingulotomy resulted in freedom from seizures and significant improvement in her obsessive-compulsive symptoms.