Understanding Neurology

200Acute hypertensive crisisChronic arterial hypertension of mild or moderatedegree does not cause headache. However,hypertension may be a cause of headache incircumstances where there is an acute, severe, andprolonged elevation in diastolic blood pressure. Inmalignant hypertension, diastolic blood pressure is>120 mmHg (16 kPa), there is evidence of grade 3 or4 retinopathy, the patient may be encephalopathic,and the headache is temporally related to the rise inblood pressure and disappears within 2 days of theblood pressure normalizing (7 days if encephalopathyis present). Patients with a phaeochromocytoma maypresent with headache when there is an acute rise(>25%) in diastolic blood pressure. This may beassociated with sweating, palpitations, or anxiety.The headache disappears within 24 hours of bloodpressure normalization. Patients with pre-eclampsiaand eclampsia may also present with headache whichis associated with oedema or proteinuria, and a bloodpressure rise of 15 mmHg (2 kPa) from the prepregnantlevel or a diastolic pressure of 90 mmHg (12kPa). The headache disappears within 7 days of bloodpressure normalization or termination of thepregnancy. Some toxins or medications may cause anacute rise (>25%) in diastolic blood pressureassociated with headache. The headache willdisappear within 24 hours of blood pressurenormalization.StrokeCarotid and vertebral artery dissection may cause astroke or TIA and is commonly associated withsudden onset headache ipsilateral to the affectedartery.Coital headacheCoital headache is bilateral at onset, precipitated bysexual excitement, prevented or eased by ceasingsexual activity before orgasm, and is not associatedwith intracranial pathology such as an aneurysm.There are three forms: dull, explosive, and posturaltypes. The dull form is characterized by a dull ache inthe head and neck that intensifies as sexualexcitement increases. In the explosive form, there is asudden severe headache that occurs at the time oforgasm, and in the postural form the headachedevelops after coitus and resembles that of low CSFpressure headache.Benign cough headacheCough headache is bilateral, of sudden onset, and isprecipitated by coughing. It may be diagnosed onlyafter structural lesions have been excluded byneuroimaging.Benign exertional headacheBenign exertional headache is specifically brought onby any form of physical activity. Patients complain ofbilateral, throbbing pain that normally lasts between5 minutes and 24 hours. It is prevented by avoidingexcessive exertion and is not associated with anysystemic or intracranial disorder.Idiopathic stabbing headacheIdiopathic stabbing headache is predominantly felt inthe orbit, temporal or parietal region. It is stabbing innature, lasts a fraction of a second, and recurs atirregular intervals. It should only be diagnosed afterstructural lesions have been excluded byneuroimaging.Thunderclap headacheThunderclap headache refers to patients who presentwith suspected SAH but who have a normal CT scanand CSF examination performed within theappropriate time window. This is considered to be arelatively benign condition, which does not requireany further investigations.SUMMARY❏❏❏❏❏❏❏Headache is common and for most is a benignself-limiting symptom.It is crucial to determine if the headache is newor the exacerbation of an existing headache,which has become more frequent or severe.The possibility of having a serious cause doesnot increase in proportion to the severity,frequency, or duration of the headache.Patients with tumours rarely present withheadache alone.History and examination should identify thosepatients with red flag symptoms and signs whoneed investigation.Sudden onset headache should be investigatedurgently.All patients over the age of 50 years with newonset daily headache should have their ESRchecked.