Carences en cobalamine : aspects neurologiques chez 27 patients

[Neuropsychiatric manifestations ushering pernicious anemia]

Biermer disease or pernicious anemia is an autoimmune atrophic gastritis characterized by the lack of secretion of gastric intrinsic factor. This leads to an insufficient absorption of vitamin B12 in the ileum. Clinical manifestations are mainly hematologic. Neuropsychiatric manifestations are known but are less frequent especially early in the disease. Inaugural neuropsychiatric arrays are rare and various thus making diagnosis difficult. In this article, we report through two clinical cases different neuropsychiatric manifestations revealing pernicious anemia. Mrs. C.O., aged 56, presented after surgery for gallstones, an acute psychiatric array associated with gait disorders. She had no history of neurological or psychiatric problems. The psychiatric interview revealed delirious syndrome, depressive symptoms and anxiety. Neurological examination noted a flaccid paraplegia with peripheral neuropathic syndrome and myoclonus in the upper limbs. At the full blood count, a macrocytosis (VGM: 112.2fl) without anemia was found. The level of vitamin B12 in the blood was low. Cerebro-spinal MRI was suggestive of a neuro-Biermer and showed hyper signal in the cervical cord on T2-weighted sagittal section. In axial section, hyper signal appears at the posterior columns in the form of V. There were no brain abnormalities. A sensorimotor axonal polyneuropathy was diagnosed. The patient received vitamin B12 intramuscularly for ten days associated with neuroleptic treatment. Mrs. R.M., aged 40, was brought to the psychiatry consultation for acute behavioral disorders progressively worsening over a month. An anxiety syndrome, depressive syndrome and delirious syndrome were identified. Neurological examination showed a posterior cordonal syndrome with quadripyramidal syndrome. Full blood count showed a macrocytic anemia. Serum B12 level was collapsed. Cerebro-spinal MRI was normal. She received vitamin B12 with clinical and biological improvement. Features of pernicious anemia vary according to studies and age range. Digestive and hematological manifestations are well known. Neurological and psychiatric manifestations of pernicious anemia were also described in the early literature. They can be the initial symptoms or the only ones. However, inaugural neuropsychiatric features are often unrecognized. The most common psychiatric symptoms were depression, mania, psychotic symptoms, cognitive impairment and obsessive compulsive disorder. Neurological involvement includes mainly combined spinal sclerosis, peripheral neuropathy and dementia. Cerebellar ataxia and movement disorders are reported less often. Severity of neuropsychiatric features and therapeutic efficacy depends on the duration of signs and level of B12 deficiency. Macrocytic anemia may lack. Neuropsychiatric manifestations could be isolated or be the first manifestation of vitamin deficiency and occur without any hematological or gastrointestinal context. Pernicious anemia and serum B12 assay should be discussed in all patients with organic mental disorders, atypical psychiatric symptoms and fluctuation of symptomatology. Nevertheless, B12 level could be normal in genuine pernicious anemia diseases and macrocytic anemia may lack. Substitutive vitaminotherapy is required when diagnosis is strongly suspected and etiologic assessment is negative.

[Metabolic and nutritional neuropathies: update in diabetes, vitamin B12 and copper deficiency]

Metabolic and deficiency neuropathies retain a growing interest because of their important prevalence. The dismemberment of diabetic neuropathies is proceeded, letting distinct pathophysiological mechanisms appear. So, even if glycaemic control remains determining for preventing the neuropathy associated with type 1 diabetes, it seems to have a restricted role with type 2 diabetes in which other metabolic factors are involved. The diagnosis of neuropathy due to B12 vitamin deficiency remains a real challenge for the clinician. Indeed, positive and negative predictive values of serum B12 and metabolites assay are weak, only a good therapeutic response allows a reliable diagnostic. It is so recommended to know the clinical and contextual particularities of this etiology in order to not delay the vitamin substitution, determining for the functional outcome. Finally, copper deficiency remains an unknown cause of neuropathy which is suitable to raise in case of malabsorption but also and especially in case of abuse of dental adhesive rich in zinc.

Vitamin B-12 supplementation of rural Mexican women changes biochemical vitamin B-12 status indicators but does not affect hematology or a bone turnover marker

A high prevalence of low serum vitamin B-12 concentrations has been reported in studies and surveys in Latin America including Mexico, but the functional consequences are unknown. This randomized controlled trial assessed the response to a high-dose vitamin B-12 supplementation of women in rural Querétaro, Mexico. Participants aged 20-59 y were stratified at baseline to deficient, marginal, and adequate status groups (serum vitamin B-12, 75-148, 149-220, and >220 pmol/L, respectively), and each group was randomized to vitamin B-12 treatment (single dose of 1 mg i.m. then 500 μg/d orally for 3 mo, n = 70) or placebo (n = 62). Measures at baseline and 3 mo included: complete blood count, serum vitamin B-12, holotranscobalamin (holoTC), folate, ferritin, C-reactive protein (CRP), bone alkaline phosphatase, and methylmalonic acid (MMA) and plasma total homocysteine (tHcy). At baseline, 11% of the women were vitamin B-12 deficient and 22% had marginal status. HoloTC was low (<35 pmol/L) in 23% and correlated with serum vitamin B-12 (r = 0.7; P < 0.001). Elevated MMA (>271 nmol/L) and tHcy (>12 μmol/L) occurred in 21 and 31%, respectively, and correlated with serum vitamin B-12 (r = -0.28, P < 0.0007 and r = -0.20, P < 0.01, respectively). Supplementation increased serum vitamin B-12 and holoTC and lowered MMA and tHcy, normalizing all values except for elevated tHcy in 21% of the women. Supplementation did not affect hematology or bone-specific alkaline phosphatase. Vitamin B-12 supplementation normalized biochemical indicators of vitamin B-12 status in the treatment group but did not affect the functional outcomes measured.

[Central autonomic failures]

Autonomic nervous system (ANS) modulates the function of all body organs through both parasympathetic and sympathetic fibers. Orthostatic hypotension is frequently observed in the course of central nervous system diseases including cortical (stroke, epilepsy, dementias), neurodegenerative (Parkinson's disease, multisystem atrophies) and spinal cord diseases. In some cases, the mechanism of orthostatic hypotension associated with central nervous system diseases involves a dysfunction of peripheral ANS fibers.