Pain and Neurological Disorders Flashcards
Which nerves are most commonly damaged during treatment?
How long are they affected for?
- Inferior alveolar nerve
- Lingual nerve
- During surgical removal lower 8s, implant placement, endodontic irrigation with hypochlorite
- 3/4 lingual nerve injuries resolve spontaneously in 2-3 months
- IAN effects are usually persistent, and surgical exploration should be considered within 3 months for best effect
- Prevention is key:
avoid unnecessary extractions, identify teeth close to nerve, use alternate techniques e.g. coronectomy
What can cause pain from salivary glands?
Why does pain occur immediately?
- mealtime syndrome
- acute and chronic parotitis (mumps)
- salivary obstruction (calculi, strictures)
- painful condition of intraparotid lymph nodes
- inflammatory disease of parenchyma
- malignant neoplasms with perineurial spread
- Parotid and submandibular glands cause pain immediately as there is little space for expansion and a tight capsule
What can cause TMJ pain?
- intra-capsular: degenerative conditions, neoplasia, trauma, inflammatory
- capsular: trauma including joint dysfunction
- muscles of mastication: joint dysfunction, arthromyalgia
What is primary neuralgia?
- Pain corresponds to the anatomical distribution of the nerve
What is the difference between neuropathy of sensory vs motor nerves?
- Sensory: pain, hyperalgesia, paraesthesia, analgesia, burning, altered sensation
- Motor: palsies, muscle fasciculation (twitch) and weakness
Examples of sensory and motor neuralgias and neuropathies
- Sensory: Trigeminal neuralgia MS Pain of herpes zoster Postherpetic neuralgia Intracranial tumours BMS Psychogenic pain (atypical facial pain)
- Motor: Bell's palsy Stroke Epilespy Intracranial tumours
Aetiology and characteristics of trigeminal neuralgia
- Believed to be the compression of nerve by adjacent artery - either 2nd or 3rd division of trigeminal nerve usually
- Affects older pts (50+)
- Unilateral - confined to one or more divisions
- Sudden, severe, stabbing, electric pain lasting 1-2mins
- Trigger zones within distribution of nerve
- No sensory or motor impairment
- Never at sleep
- Long intervals of remission (weeks/months)
Diagnosis of trigeminal neuralgia?
What is the most common differential diagnosis?
- Made from features described
- Dental disease can mimic
- Diff diagnosis: MS and intracranial tumours compressing the nerve - take MRI
- MS: suspect if pt younger than normal, has sensory loss, bilateral pain or pain extending beyond trigeminal area
- Intracranial tumours (rare): associated sensory loss especially if associated with cranial nerve palsies
Treatment of trigeminal neuralgia
- Reassurance
- Carbamazepine (anticonvulsant) most effective
- Combination therapy
- Surgical tx: decompression, cryotherapy, gamma knife ablation (radiation)
- Alcohol/phenol injection
Characteristics of trigeminal neuropathy
- Unlike trigeminal neuralgia, sensation is affected
- Causes pain, burning, paraesthesia, anaesthesia of part of skin in distribution of trigeminal nerve
- Usually continuous pain and may be unilateral
- No trigger zones
Aetiology and treatment of trigeminal neuropathy
- Can follow nerve ablation as a treatment for trigeminal neuralgia
- Trauma
- Intracranial neoplasms
- Metabolic/inflammatory disorders
- tx: long term analgesic nerve blocks, anticonvulsant or tricyclic antidepressants
Characteristics, aetiology and treatment of glossopharyngeal neuralgia
- Pain of same character as trigeminal neuralgia, but it felt in the distribution of glossopharyngeal (base of tongue, faces and ear on one side only)
- Triggered by swallowing, chewing or coughing
- Pressure on nerve such as intracranial tumour
- Carbamazepine (but less reliably)
Characteristics, diagnosis and treatment of postherpetic neuralgia
- Develops in pts who have had trigeminal herpes zoster (aggressive antiviral tx of acute infection reduces risk of developing this)
- Persistent pain limited to dermatome affected by zoster attack (burning, itchy, hypersensitive to touch/temp)
- History of facial zoster or presence of scars from rash for diagnosis
- Resistance to tx (poor response to surgery/carbamazepine)
- Application of transcutaneous electric stimulation to affected area by pt
Atypical facial pain features and management?
- poorly localised pain persisting for many years
- Common site: maxillary region/upper teeth
- Neurologically impossible distributions: bilateral or crossing dermatomes
- Bizarre description of pain
- No triggers
- Emotional disturbance e.g. depression
- Management tailored to any underlying mental illness
- Tricyclic antidepressant e.g. prothiaden, nortyptilline
- Phenothiazines (antipsychotic) e.g. flupenthixol, fluphenazi
What needs to be excluded before diagnosing atypical facial pain?
- Primary or secondary neuropathy
- Referred pain
- TMD muscular
- Migraine
- TAC
What is atypical odontalgia?
- Less common variant of atypical facial pain
- Pain localised to one tooth or row of teeth
- If dental disease is found, tx has no effect
- If tooth removed or root filled - pain moves to next tooth
- Early diagnosis is essential to avoid over treatment and dental morbidity
- neuralgic elements to this pain
What are the main causes of paraesthesia and anaesthesia of the lower lip (10)
- Inferior dental blocks
- Surgical damage on removal of 8s
- Fracture of mandible - nerve becomes stretched
- Acute osteomyelitis
- Malignant tumours of mandible usually metastatic
- Exposed mental foremen
- due to excessive resorption of bone in edentulous
- denture then presses on nerve
- solution: implants or relieve denture - Herpes zoster
- MS
- Tetany (muscle spasms)
- results of hypocalcaemic status causing heightened neuromuscular excitability
- Can be due to over breathing - usually anxiety
- paraesthesia is bilateral and also affects extremities - Postherpectic neuralgia (rarely lower lip alone)
What do lips signs accompanied by involvement of tongue or skin of the side of the head indicate
- Indicate a more proximal lesion affecting the posterior division of the mandibular nerve
- Further proximal lesions involve motor supply to the muscles of mastication
Causes of facial palsy?
extracranial vs intracranial
- Extracranial causes
Bell’s palsy, malignant parotid neoplasms, parotid surgery, sarcoidosis, misplaced LA, Melkersson-Rosenthal syndrome - Intracranial causes
Strokes, cerebral tumours, MS, HIV, lyme infection, Ramsay Hunt syndrome, trauma to base of skull
Damage to what nerve causes facial palsy
- Muscles of face supplied by facial nerve, so facial palsy will be caused by damage to either upper or lower motor neurones
Where do the lower facial nerve neurones pass from? LMN damage causes impairment of which facial muscles?
motor nucleus in the pons
to facial muscles
- In LMN lesions such as Bell’s palsy, there is impairment of contraction of all facial muscles
Where do the upper facial nerve neurones pass from? UMN damage causes impairment of which facial muscles?
primary motor cortex in frontal lobe
to the pons
to facial muscles
- Muscles of upper part of face receive stimuli from both sides of the brain whereas muscles in lower portion of face activated by contralateral cortex
- So UMN damage - lower face is more affected
What is the cause of Bell’s palsy and what are the clinical features?
- idiopathic aetiology
- Suspected to be caused by inflammation and swelling around the ganglion caused by viral infection (herpes zoster)
- Rapid onset
- Pain in jaw sometimes precedes paralysis
- Facial paralysis
- Speech and taste are affected
- Saliva may drool at rest from mouth
What facial movement can you ask the pt to do to test for Bell’s palsy
- ask pt to close eyes: lids on affected side cannot be brought together
- ask pt to smoke: corner of mouth on affected side does not rise and normal lines of expression are absent
wrinkling around the eyes not seen indicating LMN lesion
What is the management of Bell’s palsy
- Majority ervoer fully or partially without tx
- Prednisolone orally may be given for 5-10 days and then tapered off over the following 4 days: effective if given within 24 hours of onset
- If eye cannot close fully then must be protected
- More than half fail to recover:
disfiguring
persistent denervation develop muscle atrophy
watering of the eye due to impaired drainage of tears - Avoid exercise to help speed recovery
Dental aspects affected in pts with Bell’s palsy
- Paralysis reduces oral clearance of food, debris can accumulate
- If tx fails, sagging of affected side of the face may be limited by intramural prosthesis
- early referral important to prevent permanent disability
What is the difference between primary and secondary headaches?
- Primary headaches are a condition such as common tension headaches or migraine without underlying disease
- Secondary headaches are caused by separate disease process, such as intracranial tumour or haemorrhage
What are the signs of a secondary headache?
- Sudden onset
- Onset after trauma
- Not experienced before
- Increased frequency/severity
- Systemic symptoms
- Fever or rash
- Stiff neck
Migraine features and management
- Precipitating factos: stress, hunger, certain foods, menstruation
- Features: irregular, begins day or night and lasts 24h, intense throbbing pain, photophobia, visual disturbances, sometimes nausea and vomiting
- Management: good response to 5HT agonists, Ergotamine
Migrainous neuralgia aetiology, features and management
- Aetiology: oedema or dilation of the wall of the internal carotid
- Precipitating factors: alcohol
- Features: cluster headaches: intense unilateral orbital and temporal pain, episodic (same time every day), lasts 60mins, usually attacks recur for several days then remit for months, no photophobia
- Management: Ergotamine, analgesics, MRI to exclude other causes
Features and management of (or giant cell arteritis)
- Features: Severe persistent pain, pain in masseter, systemic features: weight loss, joint pain, visual loss
- Management: corticosteroids