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CPE-009 · synthetic case B12-FX-06

Posterior-column signs and spasticity

A pattern compatible with subacute combined degeneration.

Synthetic · no real patientAuthored by Biod · reviewed by Dr. AmaralB12 engine v1.0.0

Purpose: A pattern compatible with subacute combined degeneration.

Inputs the engine received

Laboratory

Serum vitamin B12
160 pg/mL
MCV
101 fL

Patient

Age
58 years
Sex
Male

Neurologic features

Peripheral neuropathy symptoms
Yes
Loss of vibration or proprioception
Yes
Positive Romberg
Yes
Spasticity or Babinski sign
Yes

What the engine reports

Priority

Neurologic features and B12

B12-05

Neurologic involvement can occur without anemia and raises the urgency of finding vitamin B12 deficiency. BSH advises that treatment should not wait for confirmation when neurologic involvement is present.

Detected clinical pattern

Urgent Review Finding

A safety rule calls for urgent clinical assessment. Read the safety findings first.

  • B12 level: B12 160 pg/mL · low
  • Pattern: b12 deficiency pattern

Why this pattern was identified

  • Low serum B12. 160 pg/mL is below 200 pg/mL (148 pmol/L).

Recommended next steps

For physician consideration. Urgent review always comes first.

  1. 1Urgent clinical assessment; B12 (with MMA) should not be delayed.
  2. 2Measure B12 (with MMA) promptly.BSH 2014.
  3. 3Look for the cause: pernicious anemia, diet, drugs (metformin, acid suppression, nitrous oxide) and malabsorption.
  4. 4Check B12 and folate, a reticulocyte count and a blood film; review alcohol, liver and thyroid status and drugs.

Differentials, pitfalls and contradicting signals

  • Macrocytosis has many causes beyond B12 and folate: alcohol, liver disease, hypothyroidism, reticulocytosis, myelodysplasia and drugs (hydroxyurea, methotrexate, zidovudine, azathioprine).
Evidence and rule trace · 4 rules

B12-01Low serum B12

Inputs: serum B12 160 pg/mL (<200)

Biochemical pattern compatible with vitamin B12 deficiency.

B12-07Macrocytosis work-up

Inputs: MCV 101 fL

Macrocytosis work-up.

B12-05Neurologic or psychiatric features with unmeasured or low B12

Inputs: neuropathy symptoms · B12 160 pg/mL

Neurologic involvement raises the urgency of finding B12 deficiency.

B12-06Pattern of subacute combined degeneration

Inputs: posterior-column signs or gait ataxia · spasticity or Babinski sign

Urgent: pattern compatible with subacute combined degeneration.

Evidence

  • EV-BSH-2014 · Devalia V, Hamilton MS, Molloy AM; British Committee for Standards in Haematology. Guidelines for the diagnosis and treatment of cobalamin and folate disorders. Br J Haematol. 2014;166(4):496-513.
  • EV-STABLER-2013 · Stabler SP. Vitamin B12 deficiency. N Engl J Med. 2013;368(2):149-160.

Physician adjudication required. Clinical decision support for physician review. This output identifies laboratory patterns and safety considerations. It does not diagnose, find the cause, or select a vitamin product, dose or route. Physician adjudication is required.

Change the values

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Serum B12 level

  1. ● Below 200 pg/mL

    Deficiency pattern

  2. ○ 200 to 300 pg/mL

    Borderline: MMA and homocysteine settle it

  3. ○ Above 300 pg/mL

    Deficiency unlikely, not excluded

Laboratory
  • <200
  • 200–300
  • >300
Patient
Sex
Neurologic features
Drugs, diet and risk groups

Live result · computed in your browser

Priority

Neurologic features and B12

B12-05

Neurologic involvement can occur without anemia and raises the urgency of finding vitamin B12 deficiency. BSH advises that treatment should not wait for confirmation when neurologic involvement is present.

Detected clinical pattern

Urgent Review Finding

A safety rule calls for urgent clinical assessment. Read the safety findings first.

  • B12 level: B12 160 pg/mL · low
  • Pattern: b12 deficiency pattern

Why this pattern was identified

  • Low serum B12. 160 pg/mL is below 200 pg/mL (148 pmol/L).

Recommended next steps

For physician consideration. Urgent review always comes first.

  1. 1Urgent clinical assessment; B12 (with MMA) should not be delayed.
  2. 2Measure B12 (with MMA) promptly.BSH 2014.
  3. 3Look for the cause: pernicious anemia, diet, drugs (metformin, acid suppression, nitrous oxide) and malabsorption.
  4. 4Check B12 and folate, a reticulocyte count and a blood film; review alcohol, liver and thyroid status and drugs.

Differentials, pitfalls and contradicting signals

  • Macrocytosis has many causes beyond B12 and folate: alcohol, liver disease, hypothyroidism, reticulocytosis, myelodysplasia and drugs (hydroxyurea, methotrexate, zidovudine, azathioprine).
Evidence and rule trace · 4 rules

B12-01Low serum B12

Inputs: serum B12 160 pg/mL (<200)

Biochemical pattern compatible with vitamin B12 deficiency.

B12-07Macrocytosis work-up

Inputs: MCV 101 fL

Macrocytosis work-up.

B12-05Neurologic or psychiatric features with unmeasured or low B12

Inputs: neuropathy symptoms · B12 160 pg/mL

Neurologic involvement raises the urgency of finding B12 deficiency.

B12-06Pattern of subacute combined degeneration

Inputs: posterior-column signs or gait ataxia · spasticity or Babinski sign

Urgent: pattern compatible with subacute combined degeneration.

Evidence

  • EV-BSH-2014 · Devalia V, Hamilton MS, Molloy AM; British Committee for Standards in Haematology. Guidelines for the diagnosis and treatment of cobalamin and folate disorders. Br J Haematol. 2014;166(4):496-513.
  • EV-STABLER-2013 · Stabler SP. Vitamin B12 deficiency. N Engl J Med. 2013;368(2):149-160.

Physician adjudication required. Clinical decision support for physician review. This output identifies laboratory patterns and safety considerations. It does not diagnose, find the cause, or select a vitamin product, dose or route. Physician adjudication is required.

More b12 cases

B12-FX-01

B12 of 150 pg/mL with macrocytic anemia

A 67-year-old with MCV 108.

B12-FX-02

Borderline B12 with raised MMA

B12 260 and MMA 0.52.

B12-FX-03

Borderline B12 and no confirmatory test

B12 250.

B12-FX-04

Macrocytic anemia, folic acid ordered, no B12

A safety situation.

B12-FX-05

Neuropathy, B12 220 and metformin for five years

Neurologic features with a borderline level.

B12-FX-07

Macrocytosis in a patient with alcohol use disorder

MCV 104, B12 not measured.

All b12 cases

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