Term
| Neonatal maladjustment syndrome: synonyms |
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Definition
-neonatal encephalopathy
-hypoxic ischemic encephalopathy
-dummy foal syndrome |
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Term
| Neonatal maladjustment syndrome: etiology |
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Definition
| -previously believed to be due to birth hypoxia but: gross or histologic lesions of hypoxia are rare, rarely history of dystocia, neurologic signs have delayed onset and are usually not permenent |
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Term
| Neonatal maladjustment syndrome: current theory |
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Definition
-imblanace of inflammatory mediators and neuroendocrine factors in foal's brain:
-allopregnalone-produced by placenta, keeps foals still and somnolent in utero; levels decline rapidly after birth
-pregnenalon sulphate-produced by placenta is excitatory but normally slow to cross BBB barrier |
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Term
| Neonatal malajustment syndrome notes: |
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Definition
-NMS foals may have increased inflammatory mediators causing increased BBB permeability: permits excitatory pregnenalone sulfate to cross BBB barrier; alters behavior/mentation
-if hypoxia and inflammation are controlled over time, stabilization occurs and foals recover |
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Term
| Clinical signs of Neonatal maladjustment syndrome |
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Definition
-deranged cerebral function: loss of suckle reflex, cannot find udder, aimless wandering, hyperesthesia, hyperexcitability, jerky/still movments, abnormal respiratory patterns and sounds, sometimes respiratory distress
-often later follwed by depression and unresponsiveness-hypothermia, acidosis, seizures, coma |
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Term
| Neonatal maladjustment syndrome: signs of spinal cord damage |
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Definition
-weakness: all limbs or localized to front of rear, depending on location of lesion, ataxia, depressed local reflexes
-extensor spasms of neck, limbs, tail, paddling, or more classic clonic convulsions
-or both brain and apinal syndromes can occur |
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Term
| Neonatal maladjustment syndrome dx |
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Definition
-PE, neuro exam,
-CBC (anemia, concurrent sepsis)
-Serum chemistry (renal function, liver function, electrolytes)
-important to determine if septic/better to assume so than be wrong
-CSF tape -if indicated to r/o meningitis (normal: <4 mononuclear cells/ul; protein (40-160 mg/dl); 1+ xanthochromia)
-RBCs in atraumatic tap, and/or >2+ xanthochromasia possible CNS hemorrhage
-Many NMS foals have normal CSF taps |
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Term
| Differential dx for neonatal seizures |
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Definition
1. perinatal complications: hypoxic-ischemic brain disease, intracranial hemorrhage, birth trauma with cerebral contusion
2. infection-bacterial meningitis, botulism-shaker foals
3. developmental-hydrocephalus or other malformations
4. idiopathic epilepsy in arabian foals |
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Term
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Definition
1. maintenance of body temp, hydration, caloric intake, electrolyte acid-base balance and blood glucose
2. oxygen therapy as needed
3. plasma (if IgG <800 mg/dl)
4. broad-spectrum antibiotics
5. tx of cerebral ededma (DMSO IV early, mannitol)
6. intensive physiotherapy
-> prognosis can be quite good |
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Term
| Control of convulsions (NMS) |
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Definition
1. Diazepam (Valium)-if frequent use, longer-acting anticonvulsant needed
2. Phenobarbital-raises seizure threshold
*weaning from any anticonvulsant therapy should be gradual to avoid recurrence of seizure activity |
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Term
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Definition
-highly dependent on complications >75-80% chance: if normal after birth, then began showing neuro signs, >800 mg/dl IgG, not septic
-poorer prognosis: development of septicemia, never stood up following delivery, no improvement in neuro function by day 3-4 |
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Term
| NMS: most common clinical course: |
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Definition
-inital improvement or plateau of clinical signs at about 48 hours of age, followed by gradual improvement in walking, nursing, affinity for mare, etc.
-completely normal after 8 days
-nursing care is critical to a favorable outcome |
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Term
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Definition
-involuntary alteration of motor activity, consciousness and autonomic function caused by a rapid electrical d/c from cerebral cortex
-seizures may be: partial-localized clinical signs: jaw chomping ("chewing gum fits"), tachypnea, tremor of facial muscles and jerky head movments |
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Term
| Generalized seizures are followed by: |
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Definition
| -post ictal phase=depression and temporary blindness; lasts for minutes to days following generalized seizures |
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Term
| Seizure threshold tends to be lowered when? |
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Definition
| -at quiet or pleasurable times (night) |
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Term
| Seizure threshold is low in foals whereas adult horses have a____________threshold |
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Definition
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Term
| Foals frequently demonstrate which types of seizures |
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Definition
| -mild, generalized seizures with: jaw-chomping, tachypnea, tremor of facial muscles and jerky head movments |
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Term
| List causes of seizures in foals: |
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Definition
1. neonatal maladjustment
2. trauma
3. bacterial meningitis
4. electrolytic disturbances
-kernicterus
-juvenille epilepsy (Arabians)
-idiopathic |
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Term
| list causes of seizures in adults horses: |
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Definition
-brain trauama
-hepatic encephalopathy
-equine protozoal myeloencephalitis
-intracarotid injx
-toxicities
-pituitary adenoma
-encephalopathies
-epilepsy
-intracranial mass |
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Term
| Intracranial masses etiologies: |
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Definition
1. cholesteatoma: cholesterol granuloma, older horses
2. pituitary adenoma: Cushing's, DST: cortisol >1 ug/dL
3. Neoplasia-primary (rare), secondary (uncommon)
4. Foals-Strep equi |
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Term
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Definition
-thorough hx
-PE
-CBC
-Serum biochem (electrolytes, glucose, renal and liver status)
-Ophthalmic exam (papillary edema, inc CSF pressure)
-CSF eval
-EPM testing |
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Term
| Dx: seizures (additional dxs) |
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Definition
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Term
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Definition
-RARE!
-repeated generalized or partial seizures
-normal neurologic exam between seizures
-any forebrain lesion potentially can act as a seizure focus with epilepsy beginning days to years after the inital lesion |
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Term
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Definition
-hx of head trauma, previous neuro dz?
-physical and neuro exam (may be misleading during post-ictal phase)
-video
-skull rads
-CSF tap-cytology
-testing for EPM Sarcocystic neurona (IFAT or SAG ELISA) |
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Term
| Adult epilepsy, owner should be told |
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Definition
-be told that horse is unsafe to ride until seizure-free and not on anticonvulsant meds for at least 6 months
-keep a record of seizure episodes
-if individual seizures occur <1/month and injuries don't require vet attention (med probably is not indicated)
-if cluster seizures, or status epilepticus, or >1 seizure a month, or seizures apparent->euth, or anticonvulsant |
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Term
| Anticonvulsant therapy in horses: |
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Definition
-acute control in adult horses-diazepam IV #1, if not available: alpha-2 agonist drugs (Xylazine)
-maintenance anticonvulsant therapy adult horses: owner keeps record of seizure activity and all meds given; phenobarb at 5 mg/kg SID, PO (inc 20%) |
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Term
| Anticonvulsant therapy: after control |
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Definition
-monitor serum concentrations of therapeutic ranges
-if complete seizure-free 6 months, wean off drug over 3 monts
-if seizures start again, raise dose
-IVERMECTIN SHOULD NOT BE GIVEN |
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Term
| Juvenile Epilepsy Syndrome |
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Definition
-"benign" epilepsy/ idiopathic
-arabian foals: signs of epilepsy from two day to six months; normal between; usually outgrow 12-18 months; often "cluster seizures"
-genetic mode of inheritance is unclear |
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Term
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Definition
-good if seizures can be controlled
-no sever self injury
-follow seizure guidelines for phenobarb
-after 6 months no seizures, dose can be reduced gradually and weaned off meds |
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Term
| Lavender Foal Syndrome:clinical signs |
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Definition
-aut recessive mutation
-clinical signs:
-difficult delivery
-can't stand at birth or roll into sternal position
-suckle reflex
-episodes of muscle rigidity of limbs, neck and back (opisth, paddling, some have nystagmus), resemble seizure disorder but: affected foals are NOT normal between episodes, remain alert |
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Term
| Etiology of Lavender Foal Syndrome: |
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Definition
-arabian foals
-dilute silver/lavender hair coat
-autosomal recessive |
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Term
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Definition
Human strict criteria to distinguish: sporadic idiopathic hypersomnia, narcolepsy: excessive diurnal sleep, flaccid paralysis with somatic areflexia, sleep paralysis and noctural disrupted sleep
-Vet med: not strict criteria to differentiate |
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Term
| Clinical signs of sporadic idiopathic hypersomnia |
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Definition
-buckle at fetlocks and catch themselves
-may fall to their knees
-injury to lips, face, or dorsal fetlocks or knees
-usually get up quietly within seconds to a minute
-chronic wounds on anterior sruface of fetlock
-frequent periods of sleepiness, standing base-wide with their eyelids partially closed and their heads lowered
-often occurs at an inappropriate time
-usually during quiet periods |
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Term
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Definition
-syncope and seizures are important differentials for narcolepsy
-syncope: acute collapse without warning
-seizures: increased focal or generalized tonic clonic muscle activity and post-ictal depression |
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Term
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Definition
-common in geriatric horses and Cushing's horses
-Dx/tx: based primarily on hx, characteristic clinical signs, exclusion of other possible causes of excessive sleepiness or collapse; rule in/out skeletal or neuro disorders causing reluctance to lie down: new envi, small stalls, arthritis/pain |
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Term
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Definition
-size of stall
-comfort level
-lights off to encourage horse to slee pin a recumbent position
-no fear of pasture-mates
-dietary supplementation |
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Term
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Definition
-true narcolepsy is rare
-hereditary in warmbloods, shetland ponies, and min horses: signs of daytime sleepiness and episodes of parital to total flaccid paralysis begin at several weeks of age; some form of stimulation, such as grooming or petting may induce
-prognosis is variable: some affected foals have had a decrease in severity and frequency of episodes with time |
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Term
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Definition
-Imipramine given at 1-2 mg/kg IM or IV 2 or 3 times daily
-signs may be relieved for 5 to 10 hours without side effects
-unfortunately, oral admin not reliable |
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