A nutritional deficiency masquerading as a neurological disorder: Scurvy-induced paraparesis

INTRODUCTION

Scurvy is a rare nutritional disorder due to dietary Vitamin C deficiency, but its incidence is increasing.^[1] Most cases of scurvy have been reported in children with neurodevelopmental disorders, behavioral eating disorders, and malnutrition. Common presentations are musculoskeletal manifestations (e.g., generalized pain in the lower limbs and refusal to walk), mucocutaneous manifestations (e.g., gingival bleeding and hypertrophy), hemorrhages, and constitutional symptoms (irritability, fatigue, failure to gain weight, and loss of appetite).^[2] Skeletal X-rays are crucial for the diagnosis. Classical changes at the end of long bones include ground-glass appearance, pencil-thin cortex, white line of Frankel, Wimberger’s sign, Pelkan’s spur, and subperiosteal hemorrhage.^[3] Low serum Vitamin C levels are the gold standard for the diagnosis of scurvy.

Because of the rarity of the disease and lack of exposure during medical teaching, diagnosing these cases is difficult. It mimics many hematological, rheumatological, and neurological conditions, making diagnosis more challenging.^[4] We present a case of scurvy with an acute paraparesis-like presentation.

CASE REPORT

A 5-year-old developmentally normal female presented with the inability to stand for 3 months. She had received a DPT vaccination 3 months earlier and developed a high fever afterward. The following day, she was hospitalized. Over the next 2 days, her fever improved and she was discharged. The parents noticed that she was unable to stand during illness, which was attributed to acute febrile illness and vaccination. The inability to stand persisted, without difficulty in sitting or involvement of the upper limbs. There was a history suggestive of tenderness in the lower limbs. There was no history suggestive of cerebral cortex, brainstem, or cerebellar involvement. There was no history suggestive of rash, bleeding, joint swelling, morning stiffness, trauma, pain in limbs; cardiac, gastrointestinal, and coagulation disorder as well as family history of sickle cell disease (SCD). Dietary history revealed that she primarily consumed milk, cereals, and pulses, avoiding fruits and vegetables.

On examination, she was sitting comfortably in her father’s lap, irritable during physical examination, and anemic. Lower limb examination showed tenderness on moving the knee and elbow joints. Her power in the upper limbs and trunk was normal and at least 4/5 in the lower limbs, as formal testing was not possible due to tenderness and irritability. The rest of the general and neurological examinations were normal. She had low weight, 12.5 kg (weight for height between −2 and −3 standard deviation).

Since the onset resembled acute paraparesis and was associated with fever, we considered infectious, para-infectious, or post-infectious disorders such as transverse myelitis, acute flaccid myelitis (AFM), demyelination, and Guillain-Barré syndrome (GBS). In view of moderate acute malnutrition, Vitamin B12 deficiency was also explored. Since neurological examination was normal, a diagnosis of pseudoparalysis of the lower limb was suspected, and SCD was considered due to its high prevalence in central India. Other possibilities included juvenile idiopathic arthritis, rheumatic fever, osteomyelitis, pyomyositis, juvenile systemic lupus erythematosus (SLE), and malignancies such as sarcoma and leukemia.

Investigations showed normal hemoglobin (Hb) electrophoresis, creatinine phosphokinase, C reactive protein, blood counts, rheumatoid factor, anti-streptolysin O titer, and Vitamin B12. Electrocardiogram and echocardiography were normal. Normocytic normochromic anemia (Hb 10.3 g/dL), high erythrocyte sedimentation rate (30 mm), low serum ferritin (32.6 ng/mL), and low Vitamin D (19.5 ng/mL) were reported. X-ray of the knee showed features suggestive of scurvy [Figure 1a]. Vitamin C level was deficient, 10.9 µmol/L (reference range 23–120 µmol)/L).

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Figure 1:

A 5-year-old girl with scurvy, who presented with an acute onset of inability to stand. (a) X-ray of knee joint showing white line of Frankel’s (thin arrow), Trummerfeld zone (arrow head), and Wimberger sign (thick arrow), (b) is showing posture on admission, not able to stand and irritable, (c) child was able to stand with support after 3 days of Vitamin C therapy.

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Tablet Vitamin C 500 mg twice a day was started along with dietary modifications. She began standing with support on day 3 and walking on day 10 [Figure 1b and c]. After that, the Vitamin C dosage was reduced to 250 mg twice daily.^[2,5]

DISCUSSION

In the modern world, scurvy is rare and seen predominantly in children with neurological disorders (e.g., autism, cerebral palsy, and developmental delay), malnutrition, and hematological disorders (e.g., transfusion-related iron overload).^[1,2] Our case was a healthy child with food selectivity and moderate malnutrition.

Pseudoparalysis of bilateral or unilateral lower limbs in scurvy usually has a subacute onset as limping followed by loss of ambulation.^[4,6] Our case presented with an acute paraparesis-like presentation. This mimics acute neurological disorders such as spinal cord disorders (transverse myelitis, AFM, compressive myelopathy, demyelination), peripheral nervous system disorders (GBS and acute intermittent porphyria), and acute viral myositis. A detailed history followed by a focused neurological examination can help differentiate true paraparesis from pseudoparalysis of the lower limb.

Normal neurological examination with evidence of musculoskeletal involvement (e.g., pain, tenderness, bone or joint swelling, local erythema, or warmth) suggests a localized disorder. Evidence of systemic involvement (e.g., hepatosplenomegaly, lymphadenopathy, anemia, and rash) suggests systemic disorders such as SCD, leukemia, juvenile idiopathic arthritis, autoimmune disorders (SLE), and scurvy.^[2] A clear syndromic diagnosis of true versus pseudoparalysis at initial assessment is crucial in children presenting with an inability to walk or stand, helping to avoid costly investigations such as neuroimaging and electrodiagnostic studies.^[6]

Similar to our case, scurvy rarely can present as hemarthrosis, intracranial hemorrhages, bone marrow failure, pulmonary hypertension, or high output cardiac failure and often mislead the diagnosis.^[2]

CONCLUSION

It is important to differentiate neurological paralysis from pseudoparalysis through proper history and examination. Scurvy is a rare but important differential for both acute and subacute onset pseudoparalysis of the lower limb. The presence of malnutrition, faulty diet, or neurodevelopmental disorders in such cases should raise suspicion for scurvy.