Study of the relationship between serum cortisol and dehydroepiandrosterone sulfate [DHEAS] levels and degree of cognitive impairment in the aged with Alzheimer's disease and vascular dementia

Dementia is the general term that refers to the decline of mental abilities including memory and other thinking skills while a person is alert and awake. Dementia is considered a late-life disease because it tends to develop mostly in elderly people. The two most common forms of dementia in older people are Alzheimer's disease and multi-infarct dementia [vascular dementia]. Alzheimer's disease accounts for around 60% of all cases of dementia, while vascular dementia accounts for up to 20% of all cases of dementia. Cortisol and dehydroepiandrosterone [DHEA] and its sulfate ester [DHEAS] are adrenal steroid hormones. These hormones have been suggested to have a role in many aging related diseases and perhaps in aging itself. These hormones have been shown to multiple effects on the function of the hippocampus, which is involved in learning and memory processes. These adrenal steroids may thus be associated with cognitive impairment, which is a major symptom of dementia. To study the relationship between serum cortisol and dehydroepiandroesterone sulfate [DHEAS] levels and degree of cognitive impairment in the aged persons with Alzheimer's disease and vascular dementia. Study was conducted on 30 elderly demented patients selected randomly from the general population. Their ages ranged from 52 to 85 years with a mean of 68.5 years and they were 13 males and 17 females, they were divided into two groups; group I: 15 patients [7 males and 8 females] with probable Alzheimer's disease diagnosed according to diagnostic and statistical manual of mental disorder [DSM- IV criteria], group II: 15 patients [6 males and 9 females] with vascular dementia, group III consisted of 15 elderly healthy volunteers, matched for age and sex with no evidence of dementia have been served as control group. All were submitted to morning collection of blood for determination of the plasma cortisol and DHEAS measured by chemiilluminescence. The 30 points Mini Mental State Examination [MMSE] was used to assess cognition. The present study firstly showed that mean serum cortisol level increase while mean serum DHEAS level decrease with age and mean serum cortisol levels was higher in both AD and VD than normal controls while mean serum DHEAS levels in both AD and VD] was lower than normal controls. Gender did not play a significant role in variability of cortisol and DHEAS. Also, most of Alzheimer's disease patients were none educated in comparison to vascular dementia patients and this indicates that a low level of education has been associated with a greater risk of developing AD. There is an association between serum cortisol and DHEAS levels and severity and duration of dementia and cognitive decline in demented patients. There is a strong association between cortisol and DHEAS and prevalence of dementia in the elderly. There was a trend of high serum cortisol level in males and high serum DHEAS level in females but, gender did not play a significant role in variability of cortisol and DHEAS. Low level of education has been associated with a greater risk of developing dementia and there is association between serum cortisol and serum DHEAS levels and duration and severity of dementia

Peripheral nerve affection in patients with hyperlipidemia: a clinical and electrophysiological study

Familial hypercholesterolemia is a common genetic disorder, in its heterozygous form occur in 1:500 of the general population. Peripheral neuropathy has been reported with this disorder, some related it to the use of lipid-lowering agents [statins], others related it to the disease itself. This study was conducted on 3 groups of patients: 1[st] group; 15 patients with familial hypercholesterolemia receiving statins for variable durations, 2[nd] group: 15 newly diagnosed patients with familial hypercholesterolemia not receiving statins, and a 3[rd] group: 15 healthy matching controls. None of the subjects in the 3 groups had any disease causing peripheral neuropathy e.g. diabetes mellitus, renal failure, alcohol abuse... etc. All patients and controls were subjected to nerve conduction studies in both lower limbs; sensory and motor. None of the patients or controls had symptoms or signs of peripheral neuropathy. Electrophysiohgical studies didn't show any abnormalities in 2[nd] group and controls. In patients taking statins, 3 patients had neurophysiological evidence of sensory axonal neuropathy. The results of the present study support the previous reports that statins could be a cause of sensory polyneuropathy. Further investigations are recommended to determine which patient should discontinue statin treatment and identify other treatment options

Visual evoked potentials and color doppler sonography of ocular arteries in migraineurs with visual aura

Disorders of the visual function in migraineurs have been recognized by neurophysiological methods for many years. However, studies of the cortical visual evoked potentials have yielded contradictory results. Changes in the retrobulbar hemodynamic in migraineurs with visual auras, have not been researched extensively. The aim of the present work is to study the visual evoked potentials as well as the blood flow velocity, pulsatility index [PI] and resistance index [RI] in the ophthalmic and central retinal arteries in migraine patients with and without aura. The present study included thirty five migraine patients and fifteen healthy control subjects. Twenty patients have exclusively migraine with visual aura [MA], and fifteen without aura [MO]. The study was carried out during the headache-free periods, and all the patients and control groups were subjected to: complete general examination, thorough neurological and full ophthalmic examination, pattern-shift visual evoked potential [PS-VEP] assessment, and color doppler sonography of the ophthalmic [OA] and central retinal [CRA] arteries. PS-VEP assessment showed prolongation of the N75, P100, and N 145 latencies of the MA group, than in the MO and control groups, but significant difference was found only between the N75 and N145 latencies of the MA and control groups [P= 0.032, 0.039 respectively]. The mean P100-N145 amplitude of the MO group was significantly higher than that of the control group [P=0.021]. The mean P100-N145 amplitude of the MA group was lower than that of the MO group but still higher than the control group although none of the differences reached significant level. The mean PI of OA and CRA, mean RI of CRA, and mean end diastolic velocity of the CRA were significantly higher in MA group than in the control subjects. Migraineurs without aura [MO], when compared to the controls, they showed the same trend as the MA group, but none of the differences was statistically significant. The present study gives support to the role of cerebrovascular factors and ischemic damage in the prolongation of the VEP wave latencies and decreased P100 amplitude in migraine patients with visual aura. It also showed evidence of dysfunction in the retrobulbar circulation and hemodynamic changes that may explain some of the visual symptoms reported by most migraineurs

Serum magnesium in insulin-dependent diabetic patients: Effect on peripheral nerves conduction velocity

The aim of this study was to measure the serum level of magnesium in insulin-dependent diabetic patients and the effect of magnesium depletion on the conduction velocity in the peripheral nerves of the lower limbs. This study was conducted on 45 subjects divided into 3 groups: Group Ia: 15 diabetic subjects [type I] with serum Mg level /= 1.7mEq/L. Group II: 15 healthy control subjects. All subjects were studied by proper history and clinical examination, routine laboratory investigations, HbAlc, serum magnesium level and nerve conduction study of common peroneal, posterior tibial, and sural nerves. Our findings showed decrease serum magnesium levels in diabetic groups than in control group [F= 67.823, P= 0.000], and those subjects with hypomagnesemia showed a significant decrease in motor nerves conduction velocity; common peroneal, and posterior tibial nerves [F= 17.954, 31.452, and P= 0.000] as well as a significant decrease in sensory nerve conduction velocity; sural nerve [F= 19.889, P= 0.000]. Significant negative correlations were found between fasting and post prandial plasma glucose, HbA1c, and serum magnesium level [P= 0.000]. Significant positive correlations were found between serum magnesium level and nerve conduction velocity [motor and sensory]. Hypomagnesemia in type-1 diabetes mellitus may be responsible about bad control of diabetes as well as occurrence of complications, especially neuropathy. Motor and sensory nerves conduction velocity decreased significantly and positively correlated with serum micro g level. Mg supplementation in large doses may improve nerve conduction