Neurological Impact on Oral Health

Neurological Disease Overview

• Neurological diseases impact oral health and dental care greatly
• Common neurological disorders include epilepsy, multiple sclerosis, and Parkinson's disease

Intended Learning Objectives

• Identify oral diseases arising from common neurological conditions
• Understand the effects of neurological disorders on delivering oral healthcare

Neurological Disease Causes

• Neurological tissues (gray or white matter), meninges, and blood supply are all affected

• Causes of neurological disease are either genetic or acquired

• Genetic examples: Huntington's chorea, Tuberous sclerosis, many others

• Acquired examples:

  • Degenerative: Parkinson's disease, dementia
  • Vascular: Arteriosclerosis (stroke)
  • Neoplastic: primary or secondary
  • Infective: encephalopathies (e.g., herpes, measles, mumps)
  • Inflammatory: multiple sclerosis

• Many diseases may also have seizures as a feature

Epilepsy and Seizures

• Epilepsy: Paroxysmal dysfunction of brain neurophysiology (EEG). Accompanied by paroxysmal dysfunction in brain action (cognitive, behavioral, sensory, and experiential). Presents a tendency to recur
• Seizure: Transient occurrence of signs and/or symptoms due to abnormal, excessive, or synchronous neuronal activity in the brain

Epilepsy and Seizures: Basic Background

• Affects 50 million globally, with possible prevalence of 1% in some populations
• Causes vary by age group
  • Young age group: Idiopathic, Developmental lesion, Tumor, Head injury
  • Older age group: Cerebro-vascular, Tumor, Head injury, Alzheimer's disease, Medications, Metabolic disturbance (alcohol/drug)

Epilepsy- the basic clinical features

• Highly variable but for simplicity in oral health care, epilepsy can be categorized as absence or "grand mal" episodes, often with an aura prior.
• Aura: variable features (see below)
• Tonic phase
• Clonic phase
• Recovery

Epilepsy - What is Aura?

• Aura is a single symptom as part of an epilepsy episode
• Common symptoms include déjà vu, jamais vu, smells, sounds, tastes, visual changes, racing thoughts
• Acting quickly is crucial in recognizing and treating auras, as well as obtaining medical attention

Epilepsy: Management

• Medical: Anti-epileptic drugs (AEDs) like phenytoin, valproate. Ketogenic diet (children).
• Surgical: Deep brain stimulators, Vagus nerve stimulation, Neurosurgery

Implications of Epilepsy on oral health care

• Access to care: risk assessment, risk of seizure and trauma from care procedures
• Communication: typically not an issue
• Consent: unlikely to be an issue unless a seizure occurs
• Education: risk of phenytoin-induced gingivitis, risk of dental pain inducing seizures
• Surgical: no significant concerns with LA/inhalation or IV sedation. GA is not contraindicated
• Oral trauma can lead to replacement with fixed appliances rather than removable ones, to avoid airway complications
• Spread: No risks from spread.
• Seizures: ensure patient safety by limiting movement, removing sharp objects, consider administering midazolam if status epilepticus is likely. Avoid using fingers to clear the mouth

Multiple Sclerosis: Basic Epidemiology

• Affects around 2.5 million people globally
• More frequent in non-equatorial countries, Northern Europeans, and Caucasians than Hispanics or African Americans, and rare in Asians
• Typically diagnosed between 20 and 50 years of age, occasionally in young children or older adults
• Affects both genders

Multiple Sclerosis: Basic Pathology

• Demyelination (usually in the CNS)
• Dissemination in time and space: evidence of scarring (plaques) in at least two separate areas of the CNS. Evidence that the plaques occurred at different points in time.
• There is no other explanation for these changes

Multiple Sclerosis: Basic Clinical Features

• Cerebral hemispheres: mood, memory, and cognitive disturbances
• Brain stem: double vision, slurred speech, sensory and motor disturbances
• Cervical spinal cord: Various sensory and motor disturbances (including long tract involvement).
• Lumbosacral spinal cord: paraplegia, incontinence, sexual dysfunction, optic nerve damage
• Other features: fatigue, various vision problems, bladder/bowel dysfunction, numbness/tingling, muscle spasms, stiffness, weakness, tremor, mobility problems, pain (trigeminal neuralgia) cognitive problems (memory, processing), emotional fluctuations, speech/swallowing problems, heat sensitivity, sexual problems

Multiple Sclerosis: 4 Types

• Relapsing-remitting MS (RRMS): 85%
• Primary progressive MS (PPMS): 15%
• Secondary progressive MS (SPMS): 65%
• Progressive relapsing MS (PRMS): 5%

Multiple Sclerosis: Therapies

• Disease modification therapies: Azathioprine, Methotrexate, Mitoxantrone, Monthly administration of methylprednisolone, IVIgG, Cladribine, Cytoxan, Bone Marrow Transplantation, Others (treatment has greatly changed with availability of biological agents)

Multiple Sclerosis: Treatment Plan Team

• Neurologist, Dentist, Speech/language therapist, Neuropsychologist, Psychotherapist, Urologist, Social worker, and Nurse

Implications of Multiple Sclerosis on Oral Health Care

• Access to care: No significant concerns with local or intravenous anesthetics. GA is not contraindicated
• Communication: No significant issues, but can be compromised with disease progression
• Consent: No significant issues, unless patient has compromised cognition
• Education: Risk of oral dryness caused by many drugs
• Surgical: No significant concerns LA/inhalation or IV sedation. GA is not contraindicated
• Oral features: drug-induced dryness
• Orofacial features: Trigeminal neuralgia, Trigeminal neuropathy (paraesthesia or anaesthesia), Facial nerve weakness (rare), Loss of mastication function (very rare)
• Spread: No spread risks

Parkinson's Disease: Basic Epidemiology

• Worldwide, incidence is 1 in 3,000
• Prevalence increases with age
• Male to female ratio is 1.46
• Becoming increasingly common

Parkinson's Disease: Basic Pathology

• Progressive neurodegenerative disease impacting dopaminergic neurons in the substantia nigra
• Potential causes and protections suggested
• Risk factors: Genetics, head trauma (boxing, Muay Thai), toxin exposure (pesticides, herbicides)
• Protective factors: Smoking, caffeine consumption, black tea

Parkinson's Disease: Basic Clinical Features: Motor

• Motor features: Dyskinesia, Akinesia, Bradykinesia, Postural instability and gait disturbance
• Other features: Dysphagia, speech changes, drooling, scoliosis, leg deformities

Parkinson's Disease: Basic Clinical Features: Non-Motor

• Autonomic dysfunctions: orthostatic hypotension, sweating, gastrointestinal disturbances, weight loss.
• Sensory disturbances: visual hallucinations, anosmia (loss of smell), chronic pain
• Neurological deficits: cognitive impairment, dementia, psychosis, hallucinations, affective disorders
• Sleep disturbances: REM sleep behavioral disorders, vivid dreaming, insomnia, daytime hypersomnolence

Parkinson's Disease: Medical Management

• Medical: Levodopa and combinations (carbidopa), Dopamine agonists, MAO-B inhibitors, COMT inhibitors, and anticholinergics
• Surgical: Deep brain stimulation (Subthalamus nucleus (STN), Globus Pallidus interna (GPi), Lesioning (thalamus, Globus Pallidus)

Parkinson's Disease: Supportive Management

• Physical therapy: general, treadmill training, dance, martial arts, cuing
• Strength training: weight machines, resistance cycling
• Occupational therapy: dysphagia support, utensil recommendations
• Speech and language therapy: compensatory and rehabilitative approaches for dysarthria and dysphagia

Implications of Parkinson's disease on oral health care

• Access to care: Mobility impairment (wheelchairs, limited movement, balance issues. Difficulty attending appointments due to fatigue, mood changes). Additional clinical time.

• Communication: Possible compromise due to dementia (with severe disease), mood swings, slow speech, reduced vocal volume.

• Consent: Can be compromised by dementia

• Education: Risk of oral dryness from medications, modification in oral hygiene methods due to motor defects

• Surgical: Generally no significant concerns with LA/inhalation or IV sedation. GA is still an option

• Oral features: Oral dryness, principally drug induced. -Orofacial features: Dyskinesias, drooling, and other possible features (see following slides).

• Spread: No spread risks

General Key Points on Neurological Diseases

• Epilepsy has a low likelihood of seizure during oral health care delivery.
• Multiple sclerosis is increasingly common and impacts access to care.
• Parkinson's disease can significantly impede access to care.
• Staff needs awareness of potential issues and adaptations in appointment timing, clinic layout, and communication style.

Reading Material

• Students should review relevant teaching from second and fourth years.
• Special Care Dentistry (Scully, Diz Dios, Kumar, 2007) is a useful textbook.