Buckthorn Berry Intoxication

Epidemiology

Due to ingestion of fruit from the flowering shrub/small tree, Karwinskia humboldtiana (aka Coyotillio or Humboldt Coyotillo) in the buckthorn family (Rhamnaceae)
Geographic Distribution: Karwinskia humboldtiana plant is found in the southwestern US and Mexico
Prevalence in Humans: children are the most commonly affected
Prevalence in Animals: cattle and goats are the most commonly affected
- Cattle are the most susceptible
- In animals, disease is called “Limberleg”: presents with incoordination and ataxia

Exposure: ingestion of buckthorn fruit (Karwinskia humboldtiana)
- Severity of toxicity is proportionate to the amount of fruit ingested
Toxic Substance: Peroxisomicine (aka T-514, Tullidol)
Mechanism
- Peroxisomicine destroys peroxisomes -> generation of free radicals -> lipoperoxidation of cell membranes -> cell death
- Peroxisomicine specifically targets thick, distal nerve segments, resulting in demyelination
- Histologically, there is widening of the periaxonal space and a redistribution of axonal organelles to a marginal position
- Eventually, axons undergo wallerian degeneration

Demyelinating Peripheral Neuropathy (see Peripheral Neuropathy)
- Diagnosis
  - LP: normal CSF
- Clinical
  - Latency of Onset: 5-20 days after ingetsion
  - Course: rapid progression
  - Motor Findings
    - Lower>upper extremity weakness
    - May progress to severe quadriparesis with bulbar and respiartory involvement
    - Cranial Nerves: normal
  - Sensory Findings: mild and distal
  - Pathology
    - Segmental demyelination ± axonal swelling and loss
    - Experimental: axonal loss (motor) is more prominent with systemic experimental administration of toxin
    - Occasional degeneration of skeletal muscle fibers
- Treatment: supportive care
- Prognosis: may improve spontaneously over 3-12 mo
Muscle Cramps

Acute/Chronic Hypoventilation (see Acute Hypoventilation and Chronic Hypoventilation)
- Due to phrenic neuropathy

http://neuromuscular.wustl.edu/nother/toxic.htm
Intoxication with buckthorn (Karwinskia humboldtiana): report of three siblings. Pediatr Dev Pathol. 2007 Jan-Feb;10(1):66-8 [MEDLINE]
Karwinskia humboldtiana (buckthorn) fruit causes central nervous system damage during chronic intoxication in the rat. Toxicon. 2009 May;53(6):645-51 [MEDLINE]