Eyas Othman MD
Dizziness is one of the most common complaints with which patients present. In spite of this the cause often remains undetermined and this is due to the complexity of the equilibrium system, the lack of a shared vocabulary for describing dizziness, the numerous causes of dizziness, and the fact that these are not confined to the area of expertise of any particular medical specialty. The general practitioner must be able to evaluate dizzy patients and be able to identify serious problems or conditions that are specifically treatable, and know when to ask for special tests or to refer.
The History in Vertiginous Patients
- Vertigo: illusion of movement relative to one’s surrounding, usually rotatory but may be linear. This sensation usually suggest peripheral vestibular system disorders.
- Dysequilibrium or imbalance: usually patients complain of unsteadiness related to ambulation . This suggests peripheral nervous system or cerebellar disorders.
- Presyncope: feeling of faintness or impending loss of consciousness and usually related to cardiovascular disorders.
- Lightheadedness: non specific sensation of unsteadiness or floating. The causes are varied, for example, hypoglycemia, hyperventilation, anemia, drugs; in addition vestibular disturbances may present with this complaint.
- Duration of symptoms: Sudden onset or intermittent symptoms usually indicate a peripheral cause while more constant or progressively worsening symptoms indicates central cause. See Table.
- Associated symptoms : Hearing loss, ear fullness, tinnitus and ear discharge indicate peripheral vestibular pathology, while CNS symptoms such as blurred vision, diplopia, dysarthria, incontinence, motor or sensory deficit indicate central pathology. Nausea and vomiting are commonly associated with all types of dizziness but may be more marked when the peripheral vestibular system is involved.
- Exacerbating factors : Symptoms that worsen with head movement indicate a peripheral and more benign etiology, symptoms that worsen with closing the eyes indicate a peripheral vestibular cause and symptoms worsened by loud noise suggest perilymphatic fistula.
- Medical history : History of autoimmune disease, hyperlipidemia, cerebrovascular accident, migraine, seizure, cancer, syphilis and previous ear surgery may be relevant to patient symptoms. All drugs taken currently should be recorded for the possible risk of ototoxicity.
- Screening blood tests might include CBC and differential, ESR, TSH, lipid profile, syphilis screening and serology for autoimmune disease if indicated.
- Pure tone audiometry to detect any hearing loss, and auditory brainstem response (ABR) if asymmetrical hearing loss is present.
- CT or MRI is indicated if there is unexplained neurological findings or retrocochlear hearing loss, although MRI is more sensitive for detecting acoustic neuromas and demyelinating plaques of multiple sclerosis, CT scan is the test of choice for visualization bony structures of the labyrinth.
Differential Diagnosis of Vertigo
- Acute labyrinthitis
- Benign paroxysmal positional vertigo (BPPV)
- Meniere’s disease
- Perilymph fistula
- Vestibular neuritis
- Head injury, temporal bone fracture and labyrinthine concussion
- Metabolic derangement, hyperlipidemia, hypothyroidism
- Drugs eg: aminoglycosides
- Autoimmune: Collagen vascular diseases, Cogan’s syndrome, Wegener’s granulomatosis
- Systemic infections, syphilis, lyme disease
- Acoustic neuroma
- Multiple sclerosis
- Migraine headache
- Vascular insufficiency
- Temporal lobe or complex partial seizures
- Cervical vertigo