Cerebrospinal fluid lactate in dogs with inflammatory central nervous system disorders.

BACKGROUND Cerebrospinal fluid (CSF) lactate is frequently used as a biomarker in humans with inflammatory central nervous system (CNS) disorders including bacterial meningitis and autoimmune disorders such as multiple sclerosis. HYPOTHESIS Cerebrospinal fluid lactate concentrations are increased in a subset of dogs with inflammatory CNS disorders. ANIMALS One hundred two client-owned dogs diagnosed with inflammatory CNS disease. METHODS Case series. Cases were identified both prospectively at the time of diagnosis and retrospectively by review of a CSF biorepository. Cerebrospinal fluid lactate was analyzed with a commercially available, handheld lactate monitor. Subcategories of inflammatory disease were created for comparison (eg, steroid-responsive meningitis arteritis, meningoencephalitis of unknown etiology). RESULTS Cerebrospinal fluid lactate concentrations were above reference range in 47% of dogs (median, 2.5 mmol/L; range, 1.0-11.7 mmol/L). There was no significant difference in lactate concentrations between disease subcategories (P = .48). Significant but weak correlations were noted between CSF lactate concentration and nucleated cell count (r = .33, P < .001), absolute large mononuclear cell count (r = .44, P < .001), absolute small mononuclear cell count (r = .39, P < .001), absolute neutrophil cell count (r = .24, P = .01), and protein (r = .44, P < .001). No correlation was found between CSF lactate concentration and CSF red blood cell count (P = .58). There was no significant association of CSF lactate concentration with survival (P = .27). CONCLUSIONS AND CLINICAL IMPORTANCE Cerebrospinal fluid lactate concentrations could serve as a rapid biomarker of inflammatory CNS disease in dogs

Cerebrospinal fluid lactate concentrations in dogs with seizure disorders.

BACKGROUND Cerebrospinal fluid (CSF) lactate concentrations increase after seizure activity in many human patients independent of the underlying disease process. The effect of seizure activity on CSF lactate concentration in dogs is unknown. HYPOTHESIS/OBJECTIVES Cerebrospinal fluid lactate concentration is unaffected by seizure activity in dogs and is more dependent on the underlying disease process causing the seizures. ANIMALS One-hundred eighteen client-owned dogs with seizure disorders. METHODS Case series. Cerebrospinal fluid lactate concentration was determined using a commercially available lactate monitor. Seizure semiology, time from last seizure to CSF collection, number of seizures within the 72 hours preceding CSF collection, and clinical diagnosis were recorded. RESULTS Dogs with focal seizures had higher CSF lactate concentrations than did those with generalized seizures (P = .03). No differences in lactate concentrations were found among dogs with single seizures, cluster seizures or status epilepticus (P = .12), among dogs with CSF collection at different time points after the last seizure activity (P = .39) or among dogs having different numbers of seizures within the 72 hours preceding CSF collection (P = .42). A significant difference (P = .001) was found in CSF lactate concentrations among diagnostic groups, and dogs with inflammatory and neoplastic disease had higher concentrations than did dogs with idiopathic or unknown epilepsy. CONCLUSIONS AND CLINICAL IMPORTANCE Cerebrospinal fluid lactate concentration is minimally affected by seizure activity in dogs and increased concentrations are more likely associated with the underlying disease process

A mutation in MTM1 causes X-Linked myotubular myopathy in Boykin spaniels.

The purpose of this study was to report the findings of clinical and genetic evaluation of a 3-month old male Boykin spaniel (the proband) that presented with progressive weakness. The puppy underwent a physical and neurological examination, serum biochemistry and complete blood cell count, electrophysiological testing, muscle biopsy and whole genome sequencing. Clinical evaluation revealed generalized neuromuscular weakness with tetraparesis and difficulty holding the head up and a dropped jaw. There was diffuse spontaneous activity on electromyography, most severe in the cervical musculature. Nerve conduction studies were normal, the findings were interpreted as consistent with a myopathy. Skeletal muscle was grossly abnormal on biopsy and there were necklace fibers and abnormal triad structure localization on histopathology, consistent with myotubular myopathy. Whole genome sequencing revealed a premature stop codon in exon 13 of MTM1 (ChrX: 118,903,496 C > T, c.1467C>T, p.Arg512X). The puppy was humanely euthanized at 5 months of age. The puppy's dam was heterozygous for the variant, and 3 male puppies from a subsequent litter all of which died by 2 weeks of age were hemizygous for the variant. This naturally occurring mutation in Boykin spaniels causes a severe form of X-linked myotubular myopathy, comparable to the human counterpart

Cerebrospinal fluid lactate in dogs with inflammatory central nervous system disorders

BACKGROUND Cerebrospinal fluid (CSF) lactate is frequently used as a biomarker in humans with inflammatory central nervous system (CNS) disorders including bacterial meningitis and autoimmune disorders such as multiple sclerosis. HYPOTHESIS Cerebrospinal fluid lactate concentrations are increased in a subset of dogs with inflammatory CNS disorders. ANIMALS One hundred two client-owned dogs diagnosed with inflammatory CNS disease. METHODS Case series. Cases were identified both prospectively at the time of diagnosis and retrospectively by review of a CSF biorepository. Cerebrospinal fluid lactate was analyzed with a commercially available, handheld lactate monitor. Subcategories of inflammatory disease were created for comparison (eg, steroid-responsive meningitis arteritis, meningoencephalitis of unknown etiology). RESULTS Cerebrospinal fluid lactate concentrations were above reference range in 47% of dogs (median, 2.5 mmol/L; range, 1.0-11.7 mmol/L). There was no significant difference in lactate concentrations between disease subcategories (P = .48). Significant but weak correlations were noted between CSF lactate concentration and nucleated cell count (r = .33, P < .001), absolute large mononuclear cell count (r = .44, P < .001), absolute small mononuclear cell count (r = .39, P < .001), absolute neutrophil cell count (r = .24, P = .01), and protein (r = .44, P < .001). No correlation was found between CSF lactate concentration and CSF red blood cell count (P = .58). There was no significant association of CSF lactate concentration with survival (P = .27). CONCLUSIONS AND CLINICAL IMPORTANCE Cerebrospinal fluid lactate concentrations could serve as a rapid biomarker of inflammatory CNS disease in dogs