Refractory epileptic seizures due to vitamin B6 deficiency in a patient with Parkinson's disease under duodopa® therapy

Seizures due to pyridoxine deficiency in Parkinson's disease

Parkinson's disease (PD) is a complex neurodegenerative disorder characterized not only by its hallmark motor symptoms but also by a myriad of non-motor manifestations, including cognitive decline, autonomic manifestations, and gastrointestinal disturbances. Amidst these, a lesser-known but critical aspect is the increased risk of functional deficiency of pyridoxine (vitamin B6) in patients with PD, which is linked to an increased risk of seizures. This review investigates the intersection of PD, new-onset seizures, and pyridoxine deficiency, aiming to elucidate the significance of these associations and their contributions to the neurologic burden in PD. Case reports documenting the occurrence of seizures in patients with PD, particularly in the context of high-dose dopaminergic therapy and the subsequent revelation of pyridoxine deficiency were included. These cases, which often featured extensive workups revealing unremarkable findings aside from pyridoxine deficiency, underscore the multifaceted nature of PD and its treatment-related complications. The findings in these case reports suggest that dietary insufficiencies, gastrointestinal dysfunctions, and drug-nutrient interactions may eventually precipitate pyridoxine deficiency, which in turn may lead to seizures by disrupting GABAergic neurotransmission. This sheds the light on the need for increased clinical awareness and routine monitoring of pyridoxine levels in patients with PD, especially those undergoing significant therapeutic adjustments or exhibiting comorbidities that might interfere with their dietary intake such as gastrointestinal manifestations or depression. Such proactive measures could potentially mitigate the impact of this complication in patients with PD, ultimately enhancing patient care and quality of life.

Homocysteine, vitamin B metabolites, dopamine-substituting compounds, and symptomatology in Parkinson's disease: clinical and therapeutic considerations

Emerging studies suggest a correlation between elevated plasma homocysteine (hcy) levels and the risk of atherosclerosis, vascular disorders, and neurodegenerative diseases, including Parkinson's disease (PD). This narrative review delves into the intricate relationships between Hcy, vitamin B metabolites, dopamine-substituting compounds, and various symptoms of PD. Patients undergoing a long-term L-dopa/dopa-decarboxylase inhibitor (DDI) regimen, especially without a concurrent catechol-O-methyl transferase (COMT) inhibitor or methyl group-donating vitamin supplementation, such as vitamins B6 and B12, exhibit an elevation in Hcy and a decline in vitamin B metabolites. These altered concentrations appear to be associated with heightened risks of developing non-motor symptoms, including peripheral neuropathy and cognitive disturbances. The review underscores the impact of levodopa metabolism via COMT on homocysteine levels. In light of these findings, we advocate for the supplementation of methyl group-donating vitamins, notably B6 and B12, in patients undergoing a high-dose L-dopa/DDI regimen, particularly those treated with L-dopa/carbidopa intestinal gel (LCIG) infusion.

A systematic review of the potential consequences of abnormal serum levels of vitamin B6 in people living with Parkinson's disease

The prevalences of polyneuropathy and epilepsy are higher in people living with Parkinson's disease (PwPD) when compared to older adults. Vitamin B6 is widely available and affordable. PwPD are at higher risk of having abnormal serum levels of vitamin B6, which are associated with polyneuropathy and epilepsy that are potentially preventable and treatable. Potential contributors to abnormal B6 levels in PwPD include age, dietary habits, vitamin supplement misuse, gastrointestinal dysfunction and complex interactions with levodopa. The literature on the potential consequences of abnormal B6 levels in PwPD is limited by a small number of observational studies focused on polyneuropathy and epilepsy. Abnormal B6 levels have been reported in 60 of 145 PwPD (41.4% relative frequency). Low B6 levels were reported in 52 PwPD and high B6 levels were reported in 8 PwPD. There were 14 PwPD, polyneuropathy and low B6. There were 4 PwPD, polyneuropathy and high B6. There were 4 PwPD, epilepsy and low B6. Vitamin B6 level was low in 44.6% of PwPD receiving levodopa-carbidopa intestinal gel and in 30.1% of PwPD receiving oral levodopa-carbidopa. In almost all studies reporting low B6 in PwPD receiving oral levodopa-carbidopa, the dose of levodopa was ≥1000 mg/day. Rigorous epidemiological studies will clarify the prevalence, natural history and clinical relevance of abnormal serum levels of vitamin B6 in PwPD. These studies should account for diet, vitamin supplement use, gastrointestinal dysfunction, concurrent levels of vitamin B12, folate, homocysteine and methylmalonic acid, formulations and dosages of levodopa and other medications commonly used in PwPD.

Association of Serum Pyridoxal Phosphate Levels with Established Status Epilepticus

BACKGROUND

The objective of this study was to determine the prevalence of pyridoxine deficiency, measured by pyridoxal phosphate (PLP) levels, in patients admitted to the hospital with established (benzodiazepine-resistant) status epilepticus (SE) (eSE) and to compare to three control groups: intensive care unit (ICU) patients without SE (ICU-noSE), non-ICU inpatients without SE (non-ICU), and outpatients with or without a history of epilepsy (outpatient).

METHODS

This retrospective cohort study was conducted at the University of North Carolina Hospitals and Yale New Haven Hospital. Participants included inpatients and outpatients who had serum PLP levels measured during clinical care between January 2018 and March 2021. The first PLP level obtained was categorized as normal (> 30 nmol/L), marginal (≤ 30 nmol/L), deficient (≤ 20 nmol/L), and severely deficient (≤ 5 nmol/L).

RESULTS

A total of 293 patients were included (52 eSE, 40 ICU-noSE, 44 non-ICU, and 157 outpatient). The median age was 55 (range 19-99) years. The median PLP level of the eSE group (12 nmol/L) was lower than that of the ICU-noSE (22 nmol/L, p = 0.003), non-ICU (16 nmol/L, p = 0.05), and outpatient groups (36 nmol/L, p < 0.001). Patients with eSE had a significantly higher prevalence of marginal and deficient PLP levels (90 and 80%, respectively) than patients in each of the other three groups (ICU-noSE: 70, 50%; non-ICU: 63, 54%; outpatient: 38, 21%). This significantly higher prevalence persisted after correcting for critical illness severity and timing of PLP level collection.

CONCLUSIONS

Our study confirms previous findings indicating a high prevalence of pyridoxine deficiency (as measured by serum PLP levels) in patients with eSE, including when using a more restricted definition of pyridoxine deficiency. Prevalence is higher in patients with eSE than in patients in all three control groups (ICU-noSE, non-ICU, and outpatient). Considering the role of pyridoxine, thus PLP, in the synthesis of γ-aminobutyric acid and its easy and safe administration, prospective studies on pyridoxine supplementation in patients with eSE are needed.

Parkinson's Disease: Is there a Role for Dietary and Herbal Supplements?

Parkinson's Disease (PD) is characterised by degeneration of the neurons of the nigrostriatal dopaminergic pathway of the brain. The pharmacological cornerstone of PD management is mainly the use of dopamine precursors, dopamine receptor agonists, and agents that inhibit the biochemical degradation of dopamine. While these drugs initially provide relief to the symptoms and improve the quality of life of the patients, progression of the underlying pathological processes, such as oxidative stress and neuroinflammation (which have been strongly associated with PD and other neurodegenerative disorders), eventually reduce their benefits, making further benefits achievable, only at high doses due to which the magnitude and frequency of side-effects are amplified. Also, while it is becoming obvious that mainstream pharmacological agents may not always provide the much-needed answer, the question remains what succour can nature provide through dietary supplements, nutraceuticals and herbal remedies? This narrative review examines current literature for evidence of the possible roles (if any) of nutraceuticals, dietary supplements and herbal remedies in the prevention or management of PD by examining how these compounds could modulate key factors and pathways that are crucial to the pathogenesis and/or progression of PD. The likely limitations of this approach and its possible future roles in PD prevention and management are also considered.

Toward Eradication of B-Vitamin Deficiencies: Considerations for Crop Biofortification

'Hidden hunger' involves insufficient intake of micronutrients and is estimated to affect over two billion people on a global scale. Malnutrition of vitamins and minerals is known to cause an alarming number of casualties, even in the developed world. Many staple crops, although serving as the main dietary component for large population groups, deliver inadequate amounts of micronutrients. Biofortification, the augmentation of natural micronutrient levels in crop products through breeding or genetic engineering, is a pivotal tool in the fight against micronutrient malnutrition (MNM). Although these approaches have shown to be successful in several species, a more extensive knowledge of plant metabolism and function of these micronutrients is required to refine and improve biofortification strategies. This review focuses on the relevant B-vitamins (B1, B6, and B9). First, the role of these vitamins in plant physiology is elaborated, as well their biosynthesis. Second, the rationale behind vitamin biofortification is illustrated in view of pathophysiology and epidemiology of the deficiency. Furthermore, advances in biofortification, via metabolic engineering or breeding, are presented. Finally, considerations on B-vitamin multi-biofortified crops are raised, comprising the possible interplay of these vitamins in planta.

Clinical management of patients with advanced Parkinson's disease treated with continuous intestinal infusion of levodopa/carbidopa

Patients with Parkinson's disease often have a good initial response to dopaminergic therapy but later usually develop motor fluctuations and dyskinesia. In these patients, continuous infusion of levodopa-carbidopa intestinal gel (LCIG) allows for maintaining adequate dopamine levels and for improving motor and nonmotor symptoms, as well as quality of life and autonomy. Adequate candidate selection and follow-up are crucial for treatment success. Management should be multidisciplinary, and patient and caregiver education is a priority. This expert consensus document has been developed by a team of neurologists, gastroenterologists and nurses who have a vast experience in LCIG therapy, with an intention to provide knowledge and tools to facilitate patient management throughout all phases of LCIG treatment process.

Drug therapy for Parkinson’s disease: An update

Parkinson’s disease (PD) is the most common neurodegenerative movement disorder, affecting about 1% of the population above the age of 65. PD is characterized by a selective degeneration of the dopaminergic neurons of the substantia nigra pars compacta. This results in a marked loss of striatal dopamine and the development of the characteristic features of the disease, i.e., bradykinesia, rest tremor, rigidity, gait abnormalities and postural instability. Other types of neurons/neurotransmitters are also involved in PD, including cholinergic, serotonergic, glutamatergic, adenosine, and GABAergic neurotransmission which might have relevance to the motor, non-motor, neuropsychiatric and cognitive disturbances that occur in the course of the disease. The treatment of PD relies on replacement therapy with levodopa (L-dopa), the precursor of dopamine, in combination with a peripheral decarboxylase inhibitor (carbidopa or benserazide). The effect of L-dopa, however, declines over time together with the development of motor complications especially dyskinesia in a significant proportion of patients within 5 years of therapy. Other drugs include dopamine-receptor-agonists, catechol-O-methyltransferase inhibitors, monoamine oxidase type B (MAO-B) inhibitors, anticholinergics and adjuvant therapy with the antiviral drug and the N-methyl-D-aspartate glutamate receptor antagonist amantadine. Although, these medications can result in substantial improvements in parkinsonian symptoms, especially during the early stages of the disease, they are often not successful in advanced disease. Moreover, dopaminergic cell death continues over time, emphasizing the need for neuroprotective or neuroregenerative therapies. In recent years, research has focused on non-dopaminergic approach such as the use of A_2A receptor antagonists: istradefylline and preladenant or the calcium channel antagonist isradipine. Safinamide is a selective and reversible inhibitor of MAO-B, a glutamate receptor inhibitor as well as sodium and calcium channel blocker. Minocycline and pioglitazone are other agents which have been shown to prevent dopaminergic nigral cell loss in animal models of PD. There is also an evidence to suggest a benefit from iron chelation therapy with deferiprone and from the use of antioxidants or mitochondrial function enhancers such as creatine, alpha-lipoic acid, l-carnitine, and coenzyme Q10.

Seizures caused by pyridoxine (vitamin B6) deficiency in adults: A case report and literature review

Pyridoxine (vitamin B6) deficiency is a recognised cause of intractable seizures in neonates. However, pyridoxine deficiency related seizures in adults were rarely reported. This article reports a case of a 79 year old lady who suffered from new-onset seizures and was successfully treated with vitamin B6. The patient had chronic renal disease and weight loss due to anepithymia following a pelvic fracture. This article also reviews literatures of seizures caused by pyridoxine deficiency in adults. Seizures caused by vitamin B6 deficiency in adults may result from dietary deficiency, liver disease, pregnancy and certain medications and can be easily treated by vitamin B6 with excellent outcome. Clinicians should consider vitamin B6 deficiency as a potential aetiology of seizures, even in patients who suffer from other underlying diseases which can cause seizures.