Letter to the Editor
Neuropathy due to coexistent vitamin B12 and B6 deficiencies in patients with Parkinson's disease: A case series
Section snippets
Case 1
A 53-year-old man with history of colon cancer requiring partial colectomy and ileostomy in his mid-20s developed PD at the age of 43 years-old. He had been taking 1950 mg levodopa-equivalent daily dose for three years when he gradually developed hand numbness and paresthesias. Serology showed undetectable levels of B12 and folate. Despite receiving intramuscular cyanocobalamin (1000 mg/week) and oral folate (1 mg/day), his sensory loss continued to spread proximally. His exam was notable for
Case 2
A 75-year-old woman with PD for 6 years had been taking 1025 mg levodopa-equivalent daily dose when she gradually developed feet numbness and neuropathic pain. Exam was remarkable for reduced vibratory sense at the toes and broad-based gait. Workup showed low B12 (Table 1), for which she was started on oral cyanocobalamin (1000 μg/day). After several months, B12 remained low and she was transitioned to intramuscular cyanocobalamin (1000 μg/month). However, her symptoms progressed over a
Case 3
A 59-year-old woman with PD for 10 years had been taking 1000 mg levodopa-equivalent daily dose when she gradually developed feet numbness, tingling and pain that spread to involve her shins and hands over several weeks. Her exam showed bilateral abductor pollicis weakness and length dependent loss of vibratory sense. Laboratory workup (Table 1) showed a low-normal B12 level (243 pg/mL). EMG/NCS showed length dependent axonal sensory neuropathy (Table 2). Further workup showed low serum B6 and
Discussion
We report three cases of coexistent B12 and B6 deficiencies associated with neuropathy in patients with PD. All patients were consecutively identified within one year at a single institution, suggesting this may be an unrecognized entity. The greatest limitation of this series is the history of bowel resection in Case 1, which may at least have contributed to vitamin B6 and B12 deficiencies. However, the remoteness of this surgery (30 years prior) would not fit with the acuity of his symptoms.
Acknowledgements
The authors thank the patients, their families and their primary care physicians.
References (6)
- et al.
Neuropathy in Parkinson disease: prevalence and determinants
Neurology.
(2011 Nov 29) Associations between B vitamins and Parkinson’s disease
Nutrients.
(2015)- et al.
Effects of levodopa/carbidopa intestinal gel versus oral levodopa/carbidopa on B vitamin levels and neuropathy
Brain Behav.
(2017)
Cited by (5)
-
A systematic review of the potential consequences of abnormal serum levels of vitamin B6 in people living with Parkinson's disease
2023, Journal of the Neurological Sciences -
Oral levodopa, vitamin B6 and polyneuropathy: A case series
2023, Canadian Journal of Neurological Sciences -
Recent progress on associations of dietary nutrition and lifestyle with Parkinson's disease
2023, Journal of Environmental and Occupational Medicine