Immunological functioning in Alzheimer's disease: differential effects of relative left versus right temporoparietal dysfunction.

The cerebral hemispheres are differentially involved in regulating immunological functioning and the neuropathology associated with Alzheimer's disease (AD) is asymmetrical. Thus, subgroups of AD patients may exhibit different patterns of immunological dysfunction. We explored this possibility in a group of AD patients and found that patients with low white blood cell counts and low lymphocyte numbers exhibited better performance on tests of right temporoparietal functioning. Also, a significant positive relationship exists between lymph numbers and performance on a test of left temporoparietal functioning. Thus, some AD patients have greater immunological dysfunction based on relative left versus right temporoparietal functioning.

Mood disturbances and cognitive functioning in Parkinson's disease: the effects of disease duration and side of onset of motor symptoms.

Some research has supported differences in mood functioning in patients with Parkinson's disease (PD) whose motor symptoms begin at the left or right hemibody. Also, a relationship between disease duration and mood disturbances has been reported, but only for PD patients with right hemibody onset. There have been no investigations reported examining the potential interactions between side of onset of motor symptoms, mood, and disease duration on cognitive functioning. Hence, the purpose of this investigation was to determine whether the interaction between mood and disease duration differentially affects cognitive functioning in patients with PD whose motor symptoms begin at the left and right hemibody. A total of 33 PD patients with left hemibody onset and 29 PD patients with right hemibody onset were given a battery of tests to evaluate mood functioning and general cognitive functioning. As predicted, the results indicated that the interaction of disease duration and mood significantly predicted cognitive functioning for PD patients with right hemibody onset of symptoms but not for PD patients with left hemibody onset of symptoms. Interestingly, an unexpected finding was a significant positive relationship between disease duration and energy level for patients with left hemibody onset but not for patients with right hemibody onset. These results indicate that mood problems and disease duration interact to significantly affect cognitive functioning but only for those PD patients who experience a right hemibody onset of symptoms.

Acetylcholinesterase inhibitors reduce spreading activation in dementia.

Alzheimer's disease is associated with degeneration of the cholinergic system, which affects memory and attention functioning. Acetylcholinesterase inhibitors (AChEI) have been found to increase attention and given this effect might reduce spreading activation of memory nodes in lexical/semantic networks. We sought to determine whether this effect of AChEIs existed in a group of patients with dementia. A mixed sample of 34 patients with dementia (17 taking AChEIs and 17 not taking these medications) were administered the Controlled Oral Word Association Test and the Animal Naming Test. The average word frequency for their responses was obtained and used as a measure of spreading activation. Patients taking AChEIs had a significantly higher average word frequency for the COWAT as compared to those not taking AChEIs. No difference was found for the average word frequencies for the AN test. Administration of AChEIs appears to reduce spreading activation, possibly due to cholinergic innervations of the frontal cortex.

Carpal tunnel syndrome with normal nerve conduction studies.

The utility of electrodiagnostic testing in the evaluation of carpal tunnel syndrome (CTS) has been questioned. We studied patients who met the clinical criteria for CTS and compared patients who had normal nerve conduction studies (NCS) with patients who had abnormal NCS. We found that 25% of the CTS patients without confounding neurologic disorders had normal NCS with median palmar nerve stimulation. Patients with abnormal NCS were older and heavier and had more clinical features of CTS. NCS results could not be predicted accurately from clinical features by use of logistic regression models. This was especially true in clinically borderline cases. NCS did not predict the outcome of conservative management. We concluded that NCS provide independent information in the evaluation of suspected CTS, especially when fewer clinical criteria are present, but that NCS are not helpful in predicting the outcome of nonsurgical management.