Dementia: clinical-neurobiochemical correlations

This study aimed at correlating the cognitive impairments and their neuropathological basis in AD and VaD with the neurobiochemical changes in brain tissues using proton magnetic resonance spectroscopy [[1]H-MRS]. Twenty patients diagnosed as having dementia [10 with AD, and 10 with VaD] were included in this study and compared with 10 normal control subjects. Dementia patients were selected using DSM IVR, HIS, ADDTC and NINCDS. Patients were submitted to the following battery of investigations: Thorough clinical examination, routine Laboratory investigations, and various neuropsychological scales [MMSE, CAMCOG, Blessed DR scale, and Hamilton depression scale]. Brain MRI and MRS were done for all patients and control subjects. Cognitive impairment was significantly more prominent in AD patients compared to VaD patients. The most consistent neurochemical differences between demented patients and normal control subjects were significant reductions of the NAA/Cr and NAA/MI ratios at PCG and NAA/Cr ratio at Lt STG, and elevation of MI/Cr ratio at PCG, while the most consistent differences between AD and VaD patients were significant reductions of the NAA/Cr and NAA/MI ratios at PCG, Lt STG and elevated MI/Cr ratio at PCG in patients with A.D. Significant correlation was observed between the reduced NAA/Cr, NAA/MI and elevated MI/Cr ratio at PCG and changes in various neuropsychological variables studied in AD patients. Clinical neuropsychological testing is a fairly good tool for differentiation of the types of dementia [AD versus VaD]. However the neurochemical changes in brain tissues measured using [[1]H-MRS] are useful not only in distinguishing between dementia of the Alzheimer's type and vascular dementia but also explaining their neuropathological background

Central nervous system involvement in chronic inflammatory demyelinating polyradiculoneuropathy: a clinical, neurophysiological and radiological study

The frequency of the association between CIDP and CNS lesions is probably underestimated. To assess the frequency of CNS involvement in CIDP patients, and to study the characteristics of this possible association. Forty patients [20 males, and 20 females] aged between 19 and 50 years [mean 33.12 +/- 9.3 years] fulfilling the clinical, neurophysiological and CSF criteria of INCAT for the diagnosis of CIDP were submitted to complete general and neurological assessment, laboratory investigations, CSF analysis, neurophysiological evaluation [NC studies, evoked potentials [VEPs, BAEPs, SSEPs]], and MRI brain and spinal cord. Clinical evidences of CNS involvement were recorded in 12 patients [30%] of CIDP patients, abnormally delayed VEPs latencies were recorded in 16 patients [40%], abnormal BAEP latencies in 12 patients [30%], abnormal SSEP latencies in 22 patients [55%], and abnormal latencies in more than one modality in 13 patients [32.5%], MRIs brain and spinal cord were abnormal in 10 patients [25%]. CIDP patients with clinical and/or radiological evidences of CNS involvement had a significantly younger age of disease onset, more frequent relapsing-remitting pattern of the disease course, more prolonged disease duration, and less favorable response to therapy than those without evidences of CNS involvement. CIDP patients with delayed evoked potentials' latencies and/or MRI demyelinating lesions were more frequent in CIDP patients with clinical evidences of CNS involvement. Moreover, MRI lesions were more frequent in those having abnormal visual evoked potential responses. Finally, there was a percentage of CIPD patients who showed a subclinical central neurophysiological and/or radiological abnormalities. CIDP is frequently associated with various clinical, neurophysiological and radiological evidences of CNS involvement. MRI and evoked potentials are useful non-invasive techniques for demonstrating this association