Serum B12 deficiency; neuropsychiatric manifestations

ABSTRACT

To determine the frequency of various neurological and psychiatric symptoms associated with B12 deficiency. Observational and descriptive study. The study was conducted on patients presenting to the neurology clinics and inpatients who were admitted through the emergency department at Aga khan University Hospital Karachi, from 1 st July 2011 to March 2012. 150 patients of either gender and age more than 18 years. Detailed history was taken from all the patients with special regard to anemia. Inclusion criteria were that patients above 18 years of age of either sex with low serum B12 levels. Patients having any type of neurological tumors, major ischemic stroke, major intracranial haemorrhage, patients on neuroleptic medications and any evidence of toxin induced neuropathy were excluded. All patients underwent for specific investigation complete blood count, serum B12 levels [derived by Radio Assay method [RIA]. Further investigations Nerve Conduction Studies / Electromyography and CT Scan / Magnetic resonance Imaging of the Brain / spinal cord were carried out as and when required, depending on the clinical scenario. There were 69 [46%] males and 81 [54%] females. Female to male ratio was 10.8. The age ranged between 18 to 90 years with the mean age of 45.7+ 5.6. Out of 150 patients 107 patients [71.3%] had severe vitamin B 12 deficiency while 43 [28.7%] had mild to moderate deficiency. Neurological manifestations which were observed included; Memory was impaired in 13 [8.7%] of the patients. Dysarthia, along with other cerebellar signs [Nystagmus and dysdiadochokinesia] was present in 9 patients [6%]. 4 patients [2.7%] sought medical attention regarding their abnormal gait and their neurological examination revealed extensor planter responses and hyperreflexia. Cranial nerve examination revealed Anosmia in 2 [1.3%] and upper motor neuron facial weakness in 1 [0.66%] patients. Motor weakness was found in 2 patients [1.3%], and spasticity in 2 [1.3%] patients. 5 patients [3.3%] had sensory complains and were found to have impaired pain and touch perception. Proximal muscle weakness in one patient while another patient had asymmetric muscle weakness and rest of the patients had normal muscle power. None of the patient had autonomic dysfunction. In six neuropsychiatric problems were commonly seen in vitamin B12 deficient people. In these patients depression was observed in 16%, agitation 12.7%, memory impairment 8.7%, cerebellar signs and dysarthria 6%, sensory symptoms 3.3% and gait abnormality and hyperreflexia and extensor planters 2.7%. Various Neuropsychiatric problems are associated with vitamin B12 deficiency and the most common Neuropsychiatric illness found in these patients were depression, agitation, and memory impairment