42. Non-infectious central nervous diseases. Degenerative central nervous diseases in dogs and cats Flashcards
Granulomatous Meningoencepgalomyelitis?
GRANULOMATOUS MENINGOENCEPGALOMYELITIS
Inflammatory CNS disease in dogs (very rare in cats); Characterised
by focal/disseminated granulomatous lesions in the brain & spinal cord.
Lesions occur mainly in the white matter
Clinical signs: Seizures; Cerebello-vestibular dysfunction; Cervical
hyperaesthesia
Diagnosis
§ CSF: Mononuclear pleocytosis; ↑ Protein
§ CT; MRI: Solitary/multiple lesions; Contrast enhancement
§ Pathology
Treatment: Lifelong immunosuppression (Prednisolone;
cyclosporine)
Necrotising Encephalitis?
NECROTISING ENCEPHALITIS
Multiple cavitary necrotic inflammations in the brain
Two forms
§ Necrotising meningoencephalitis (Pug)
§ Necrotising leukoencephalitis (Yorkshire terrier)
Clinical signs
Corresponsive with the location of the lesion – Forebrain dysfunction
§ Seizures § Circling
§ ↓ Mental status § Head pressing
§ Visual deficits
Diagnosis – CSF: Mononuclear pleocytosis; ↑ Protein
Treatment: Glucocorticoids
Steroid Responsive Meningitis arteritis?
STEROID RESPONSIVE MENINGITIS ARTERITIS (SRMA)
Predisposed: Young, adult dogs
Clinical signs
§ Cervical rigidity § Anorexia
§ Hyperaesthesia § Fever
§ Rarely CNS signs
Diagnosis – CSF: Neutrophil pleocytosis with non-degenerative
neutrophils; ↑ IgA & ↑ Interleukin
Treatment: Long-term glucocorticoid therapy (+ azathioprine)
Polyradiculoneuritis?
POLYRADICULONEURITIS
Immune-mediated inflammation of the nerve roots & peripheral
nerves; “Coonhound paralysis”
Clinical signs
§ LMN paresis § Paralysis
§ Hyperaesthesia § Altered bark
Treatment: Supportive therapy; Physiotherapy
Prognosis: Spontaneous resolution in 3-6 weeks; Respiratory
paralysis → Death
Traumatic Brain Injury?
TRAUMATIC BRAIN INJURY
Occurrence: High-rise syndrome; Blunt trauma; Car accident; Dog fight
Emergency situation!
Primary brain injury:
§ Concussion
§ Contusion
§ Laceration
§ Axial haematoma
§ Entra-axial haematoma
Secondary Brain Injury
Neuronal death not attributed to the direct mechanical effect of
trauma
§ ↓ ATP → ↑ IC Ca2+ → Cellular oedema; ↑ ICP
§ Hypotension
§ Hypoxaemia
§ Hyperglycaemia
§ Excitotoxicosis
Clinical signs
Immediate
§ Loss of consciousness § Areflexia
§ Motor dysfunction § Seizures
Brain concussion
§ Neuronal function problem
§ Loss of consciousness
Brain contusion
§ Haemorrhage § Seizures
§ Loss of consciousness § Oedema
§ Functional problems
Treatment
Goal is to ↓ secondary brain injury by
§ Supply the brain with adequate blood + O2
§ Normalise electrolytes
§ Normalise pH
§ Normalise ICP
Polytrauma treatment
Extracranial stabilisation
Treat the life-threatening injuries
Intracranial stabilisation
Treatment of the brain injury
§ Maintain blood flow & O2 supply to the brain
§ Treat intracranial hypertension
§ Treat seizures
§ Monitor neurological state
Prevention of cerebral oedema
There should be monitoring for any intracranial hypertension
Sign of worsening neurological condition: Cushing response
§ Severe intracranial hypertension
§ ↑ BP → Reflex bradycardia
Treatment for cerebral oedema
§ Hypertonic NaCl; Mannitol infusio
Hyperthermia?
HYPERTHERMIA
Causes: Environmental heat; Excess air humidity; Physical activity;
Long, thick coat; Dyspnoea; Ø Access to water; Seizures; Malignant
hyperthermia – Inhalation of narcotics; Muscle relaxants
Clinical signs
§ Tachypnoea § Apathy
§ Weakness § Shock
§ Tachycardia § Stupor
§ Seizures § Coma
§ (Bloody) vomiting § Diarrhoea
Possible secondary effects
§ Cerebral oedema § DIC
§ Multi-organ failure § AKF
§ Arrhythmia cordis § Hypoglycaemia
§ Intestinal desquamation § Brain damage
§ Acute liver damage
Treatment
§ Move to a cool place; Cool the body until 39.5℃
§ Malignant hyperthermia: Dantrolene (muscle relaxant)
§ Shock: Bolus colloids/crystalloids
§ Brain oedema: Mannitol; Hypertonic NaCl infusion
§ DIC: Plasma transfusion; Heparin
