Question: Patient of 70 years with the only antecedent of being ex-alcoholic for 3 years and diagnosed with atrophic gastritis. Consultation for a 4-month evolution that began with distal and symmetrical paresthesias in the lower limbs and progressively added gait difficulty, this being impossible without help, and confusional episodes of paroxysmal presentation. On neurological examination, the cranial nerves are normal, have a slight bradypsychia, failures in deep sensation in four limbs, pseudo-dystonic attitude in the upper limbs, finger-nose dysmetria and bilateral knee heel with closed eyes, extenuated osteotendinous reflexes, bilateral Babinski and distal paresis in upper limbs. Point out the correct answer: 
 Options:  <1> Perform a blood count and determination of B12 when funicular myelosis is suspected. <2> Perform an MRI looking for atrophy of vermis and cerebellar foliae before the high suspicion of alcoholic cerebellar degeneration. <3> Initially, 100 mg of intravenous thiamine should be administered because of suspicion of Wernicke-Korsakoff encephalopathy. <4> The first thing to do would be a determination of natremia to rule out a central pontine myelinolysis. <5> Perform an electromyographic study when there is a high suspicion of primary lateral sclerosis.
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