Inflammation of the meninges, the membranous covering of the brain and spinal cord (meningitis), and inflammation of the brain (encephalitis) often are seen simultaneously (meningoencephalitis), although either can develop separately. Causes of meningitis, encephalitis, and meningoencephalitis include infection by bacteria, viruses, fungi, protozoa, rickettsia, or parasites. In some cases, the immune system is involved or the cause is unknown. In dogs, especially adult animals, viruses, protozoa, rickettsia, and fungi are more frequent causes of meningitis and encephalitis than are bacteria. Full article

 

2nd Ref. Meningitis, Meningoencephalitis, Meningomyelitis in Dogs

Inflammation of meninges commonly leads to secondary inflammation of the brain and/or spinal cord, resulting in various neurological complications. Long-term inflammation can also obstruct the flow of cerebrospinal fluid (CSF) — the protective and nourishing fluid that circulates around the brain and spinal cord — which leads to accumulation of CSF in the brain and thus severe complications such as seizures and paresis.  Full article

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Some info on Human study (animals are mentioned)

Encephalitis is an acute inflammation of the brain. Encephalitis with meningitis is known as meningo encephalitis. Symptoms include headache, fever, confusion, drowsiness, and fatigue. Further symptoms include seizures or convulsions, tremors, hallucinations, stroke, and memory problems. In 2013 encephalitis was estimated to have resulted in 77,000 deaths, down from 92,000 in 1990. Adult patients with encephalitis present with acute onset of fever, headache, confusion, and sometimes seizures. Younger children or infants may present irritability, poor appetite and fever. Neurological examinations usually reveal a drowsy or confused patient. Stiff neck, due to the irritation of the meninges covering the brain, indicates that the patient has either meningitis or meningo encephalitis.

The signs and symptoms of tick born encephalitis are: The virus can infect the brain (encephalitis), the meninges (meningitis) or both (meningoencephalitis). In general, mortality is 1% to 2%, with deaths occurring 5 to 7 days after the onset of neurologic signs. In dogs, the disease also manifests as a neurological disorder with signs varying from tremors to seizures and death. In ruminants, neurological disease is also present, and animals may refuse to eat, appear lethargic, and also develop respiratory signs.