A Case of Subacute Combined Degeneration of Spinal Cord Diagnosed by Vitamin B12 Administration Lowering Methylmalonic Acid

Subacute Combined Degeneration of the Spinal Cord Secondary to Nitrous Oxide Abuse

Here, we report a case of subacute combined degeneration (SCD) of the spinal cord in the setting of nitrous oxide poisoning seen at the Medical Ward, Queen Elizabeth Hospital Birmingham Our patient was a 28-year-old lady who presented with impaired sensations in the lower limbs and difficulty walking for approximately one and a half months. Her clinical symptoms did not match common neurological conditions. Upon detailed history, she revealed that she had been frequently using nitrous oxide recreationally for several years. Although her baseline investigations were normal, her magnetic resonance imaging (MRI) of the spine showed bilateral symmetrical T2 hyperintense signal changes in the dorsal columns extending from C2 to C6 spinal segment. Based on history, clinical findings, and MRI of the cervical spine, the diagnosis of SCD of the spinal cord was made, and her symptoms fully resolved with treatment.

Pernicious anemia: Pathophysiology and diagnostic difficulties

Pernicious anemia (PA) is the most common cause of vitamin B12 (cobalamin) deficiency anemia in the world. It is an autoimmune disease, comprising of salient features of autoimmune chronic atrophic gastritis (CAG) and cobalamin deficiency (CD). Although the anemia was first described as pernicious, it may well be controlled with vitamin B12 replacement. The onset and progression of PA is often insidious. Alternatively, patients may have no anemic symptoms since they become acclimatized to the subtle nature of the disease. Oftentimes, there is a possibility that the underlying disease may be missed unless a full blood count (FBC) is investigated, leading to hindrance in the treatment journey. Diagnostic challenges remain tangible for many practicing clinicians, since there is lack of reliable cobalamin assays to diagnose CD as well as clinical mimics, which simulate many other hematological conditions, such as myelodysplastic syndrome, acute leukemia, sideroblastic anemias, bone marrow failure states, thrombotic microangiopathy, and thromboembolism. Moreover, prompt recognition of the symptoms of CD is also vital, because some neurologic sequalae may become irreversible despite replenishing cobalamin. Herein, we discuss a literature review on the pathophysiology, challenging clinical presentations and diagnostic difficulties of PA. Since the cobalamin replacement therapy for PA is straightforward, it will not be discussed in this review.

Myeloradiculoneuropathy due to vitamin B12 deficiency: an unusual clinical and radiological presentation

A 42-year-old man from rural India presented with asymmetric progressive paraparesis mimicking compressive dorsal myelopathy, followed by distal upper limb, truncal and neck-flexor weakness, further complicated by acute urinary retention. His sensory deficits were marked by loss of joint position sense (JPS) and graded loss of vibration sense, along with a definite sensory level. Deep tendon jerks were hypo-to-areflexic, plantar was bilaterally extensor. He had become less attentive and occasionally failed to keep track with conversations. A syndromic diagnosis of myeloradiculoneuropathy with cognitive impairments was made. Further tailored investigations revealed vitamin B₁₂ deficiency with positive anti-parietal cell antibody. Diagnosis of subacute combined cord degeneration (SACD) was confirmed. Neuro-imaging revealed intramedullary intensity changes only along lateral aspect of spinal cord instead of characteristic posterior involvement. Following parenteral vitamin B₁₂ supplementation, patient started showing improvement in motor power and subjective sensory symptoms. His bladder symptoms persisted initially, however recovered finally after 6 months.