Khesari a cheap dal consumed in many drought prone areas of India was banned for storage or sale by the Indian Government in 1961 .But its farming is still allowed as animal feed.Many people grow this dal and eat both the dal and greens as part of their diet.I became interested in asking history of Khesari dal consumption in people, who talked about vague lower limb pain with pain causing sleeplesness .Two such patients also had associated history of burning mouth syndrome.

Since these are just observations and there are no biochemical test for checking Khesari dal toxin,and the type of neuropathy is different ,I make no claims, but mention the narrative history for documentation.

The raging debate of whether Khesari is safe or not is serious.It needs transparent reporting,testing and ethical considerations of quality of life affected by consumption of the item.There are many safer options of cheap edible grains which don’t carry risk of serious neurological damage.

In the interest of Education I am sharing a few insights from a session with AI on this topic.

Lathyrism – How to Diagnose (Practical Clinical Guide)

Lathyrism is a neurological disorder caused by chronic consumption of Lathyrus sativus (kesari dal / grass pea), leading to toxic spastic paraparesis. Diagnosis is mainly clinical, supported by dietary history and exclusion of other causes.

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✅ Clinical Diagnosis of Lathyrism

1️⃣ Key Diagnostic History (Most Important)

Dietary History

Ask specifically about:

• Chronic consumption of Lathyrus sativus (Kesari dal / grass pea)
• Duration: >2–3 months continuous intake
• Quantity: Large proportion of daily protein intake
• Circumstances:
  • Poverty
  • Famine
  • Drought
  • Food insecurity
  • Migration labor camps

📌 Classic scenario: Rural poor populations relying heavily on Kesari dal as staple food

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2️⃣ Typical Clinical Features

Motor Symptoms

• Gradually progressive spastic paraparesis
• Stiffness and weakness of both lower limbs
• Scissoring gait
• Toe walking
• Frequent falls

Neurological Signs

• ↑ Tone (spasticity) – lower limbs
• ↑ Deep tendon reflexes (knee, ankle)
• Clonus
• Extensor plantar response (Babinski +)
• No sensory loss
• No bladder or bowel involvement (early)

Upper Limbs

• Usually normal

Cranial Nerves

• Normal

📌 Pure upper motor neuron syndrome affecting lower limbs

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3️⃣ Typical Demographic Pattern

• Adolescents & young adults (15–40 yrs)
• Predominantly males
• Endemic regions:
  • India (MP, Chhattisgarh, Bihar, Odisha, UP, WB)
  • Bangladesh
  • Ethiopia

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🧠 Diagnostic Criteria (Practical)

Essential Features

1. Chronic kesari dal ingestion
2. Slowly progressive spastic paraparesis
3. Pure UMN signs
4. No sensory, bladder, or cognitive involvement

Supportive

• Epidemic clustering
• Similar cases in family/community

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🧪 Investigations (Mainly to EXCLUDE other causes)

There is NO specific diagnostic lab test for lathyrism.

Basic Workup

Test Purpose CBC, ESR Rule out infection Vitamin B12 Exclude subacute combined degeneration MRI spine Rule out compressive myelopathy, MS, tumor HTLV-1 serology Exclude tropical spastic paraparesis HIV If risk Copper levels If Wilson / myelopathy suspected

📌 MRI spine is usually normal

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🔍 Differential Diagnosis to Rule Out

Condition Differentiation Tropical spastic paraparesis (HTLV-1) Bladder symptoms, sensory changes Cervical/thoracic myelopathy MRI changes Multiple sclerosis Sensory + visual symptoms B12 deficiency Sensory loss, posterior column signs ALS LMN signs + UMN Hereditary spastic paraplegia Family history, childhood onset

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🧬 Pathophysiology (For understanding)

Kesari dal contains β-ODAP (beta-oxalyl amino alanine) → excitotoxic injury to corticospinal neurons → irreversible upper motor neuron damage

Source

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🩺 Field Diagnosis Algorithm (Simplified)

Young adult + poor socio-economic background + chronic kesari dal intake + pure spastic paraparesis → Lathyrism until proven otherwise

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🛑 Important Public Health Note (India)

Kesari dal is banned for human consumption in India, but still used illegally.Fresh green khesari contains lower levels of the neurotoxin β-ODAP compared to mature dry seeds; however, significant toxin levels persist, and chronic consumption can still result in neurolathyrism, especially in nutritionally vulnerable populations.

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Source: FSSAI https://www.fssai.gov.in/upload/advisories/2020/12/5fcdc37736f65Direction_Presence_Khesari_Gram_Dal_04_12_2020.pdf

The research is AI generated as direct experience with lathyrism is rare.

Reference

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🔬 Key PubMed Sources for Khesari Toxicity & Lathyrism

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1️⃣ Core Review: Grass Pea & Human Lathyrism

Yan ZY et al. (2006)
Lathyrus sativus (grass pea) and its neurotoxin ODAP
Phytochemistry. 2006;67(2):107–121.
PMID: 16332380

Comprehensive review of β-ODAP toxicity, clinical neurolathyrism, dietary exposure, epidemiology, and prevention.

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2️⃣ Mechanism of Neurotoxicity (β-ODAP → Neuronal Injury)

Spencer PS et al. (1991)
Gliotoxic properties of β-ODAP
Neurotoxicology. 1991.
PMID: 1802342

Demonstrates excitotoxic & gliotoxic mechanisms of β-ODAP → basis of irreversible spastic paraparesis.

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3️⃣ β-ODAP Variation in Plant Development (Green vs Mature Seeds)

Addis G & Narayan RKJ (1994)
Developmental variation of ODAP in Lathyrus sativus
Annals of Botany. 1994;74(3):209–215.

Shows ODAP varies with plant maturity — young green tissues contain lower but significant toxin levels.

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4️⃣ Environmental & Growth Factors Affecting Toxin Content

Xu Q et al. (2017)
Factors affecting β-ODAP content in Lathyrus sativus
Int J Mol Sci. 2017;18(3):526.
PMID: 28264526

Explains how drought, stress, and plant maturity affect toxin accumulation.

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5️⃣ Public Health Evidence – India (Human Consumption & Risk)

Khandare AL et al. (2014)
Grass pea consumption & neurolathyrism in Maharashtra
Indian J Med Res. 2014.
PMID: 25222783

Field data showing dose–risk relationship between grass pea intake and neurolathyrism.

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6️⃣ Indian Epidemiology – Consumption Patterns & Declining Cases

Rao GS et al. (2018)
Current scenario of Lathyrus sativus consumption in Chhattisgarh
Food Chem Toxicol. 2018.
PMID: 29908260

Demonstrates lower consumption → reduced lathyrism prevalence.

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🟢 Key Evidence Summary

Khesari causes irreversible spastic paraparesis Yan 2006; Spencer 1991
β-ODAP is neurotoxic excitatory amino acid Spencer 1991
Green khesari has lower toxin but not zero Addis & Narayan 1994
Toxin increases with maturity & stress Xu 2017
Chronic dietary exposure causes lathyrism in India Khandare 2014; Rao