Proton magnetic resonance spectroscopy in mild cognitive impairment and Alzheimer's disease: a preliminary study.

BACKGROUND: Mild cognitive impairment (MCI) is recognized as a transitional clinical state between normal aging and Alzheimer's disease (AD) and has significant higher rate of progression to AD. OBJECTIVE: To compare the changes of metabolites between AD and MCI in specific locations of the brain by using Magnetic Resonance Spectroscopy (MRS). MATERIAL AND METHOD: MMSE-Thai 2002 and neuropsychological test were performed in 17 patients with memory problem, classified into AD and MCI (10, 7 patients respectively). All patients and three age-matched cognitively normal volunteers were examined with conventional MRI and MRS of the brain. Volumes of interest were located at both-sided frontal and parietal deep white matter. NAA/Cr, Cho/Cr and mI/Cr ratios of the patients were analyzed and statistically evaluated relative to cognitively normal volunteers. Statistical analysis was performed using Cohen's kappa coefficient and Kruskal-Wallis test. RESULTS: There was no statistically significant change in metabolites in all brain regions. For AD relative to cognitively normal volunteers, there were strong tendency toward statistically significant decreased NAA/Cr at the left frontal and left parietal regions (p = 0.043 each) and decreased Cho/Cr at the left frontal region (p = 0.028). CONCLUSION: The changes of the metabolite ratios of MCI were much closer to AD. Strong tendency toward statistically significant decreased NAA/Cr in the left cerebral hemisphere, predominantly parietal region and strong tendency toward statistically significant decreased Cho/Cr at the left frontal region were indicative of neurodegeneration and replacement by gliosis. MRS may be useful for predict a chance that cognitively normal people may convert to the AD.

Severe headache with eye involvement from herpes zoster ophthalmicus, trigeminal tract, and brainstem nuclei.

A 43-year-old female presented with severe sharp stabbing right-sided periorbital and retroorbital area headache, dull-aching unilateral jaw pain, eyelid swelling, ptosis, and tearing of the right eye but no rash. The pain episodes lasted five minutes to one hour and occurred 10-15 times per day with unremitting milder pain between the attacks. She later developed an erythematous maculopapular rash over the right forehead and therefore was treated with antivirals. MRI performed one month after the onset revealed small hypersignal-T2 in the right dorsolateral mid-pons and from the right dorsolateral aspect of the pontomedullary region to the right dorsolateral aspect of the upper cervical cord, along the course of the principal sensory nucleus and spinal nucleus of the right trigeminal nerve. No definite contrast enhancement of the right brain stem/upper cervical cord was seen. Orbital imaging showed no abnormality of bilateral optic nerves/chiasm, extraocular muscles, and globes. Slight enhancement of the right V1, V2, and the cisterna right trigeminal nerve was detected. Our findings support the hypothesis of direct involvement by virus theory, reflecting rostral viral transmission along the gasserian ganglion to the trigeminal nuclei at brainstem and caudal spreading along the descending tract of CN V.