Cervicocerebral arterial dissections (CAD) are an important cause of strokes in younger patients accounting for nearly 20% of strokes in patients under the age of 45 years. Extracranial internal carotid artery dissections comprise 70%–80% and extracranial vertebral dissections account for about 15% of all CAD. Aetiopathogenesis of CAD is incompletely understood, though trauma, respiratory infections, and underlying arteriopathy are considered important. A typical picture of local pain, headache, and ipsilateral Horner’s syndrome followed after several hours by cerebral or retinal ischaemia is rare. Doppler ultrasound, MRI/MRA, and CT angiography are useful non-invasive diagnostic tests. The treatment of extracranial CAD is mainly medical using anticoagulants or antiplatelet agents although controlled studies to show their effectiveness are lacking. The prognosis of extracranial CAD is generally much better than that of the intracranial CAD. Recurrences are rare in CAD.

Levodopa is the most effective drug for treating Parkinson's disease. However, long-term use of levodopa is often complicated by significantly disabling fluctuations and dyskinesias negating its beneficial effects. Younger age of Parkinson's disease onset, disease severity, and high levodopa dose increase the risk of development of levodopa-induced dyskinesias (LID). The underlying mechanisms for LID are unclear though recent studies indicate the importance of pulsatile stimulation of striatal postsynaptic receptors in their pathogenesis. The non-human primates with MPTP-induced parkinsonism serve as a useful model to study dyskinesia. Once established, LID are difficult to treat and therefore efforts should be made to prevent them. The therapeutic and preventative strategies for LID include using a lower dosage of levodopa, employing dopamine agonists as initial therapy in Parkinson's disease, amantadine, atypical neuroleptics, and neurosurgery. LID can adversely affect the quality of life and increase the cost of healthcare.

Stroke is a recognised complication of pregnancy, contributing to more than 12% of all maternal deaths. Estimated incidence rates vary considerably from 4.3 to 210 strokes per 100 000 deliveries. Atherosclerosis is rare in young adults, and so other causes of stroke become increasingly likely. Aetiological factors important in pregnancy include hypercoagulability due to maternal physiological changes, pre-eclampsia and eclampsia, cerebral venous thrombosis, paradoxical embolism, postpartum cerebral angiopathy and peripartum cardiomyopathy. Management of patients with pregnancyrelated stroke should generally proceed as for nonpregnant patients, although there are a number of important areas specific to pregnancy which will be considered here.Stroke in young adults aged 15-35 years is more common in women than in men, 1 and women also have poorer outcomes in terms of disability and dependency.2 There has been growing interest in the role of oestrogens in stroke, 3 and risk factors unique to women include pregnancy, use of oral contraceptives, and postmenopausal hormone therapy. Stroke associated with pregnancy has been recognised for many years, and is an uncommon but feared complication contributing to more than 12% of all maternal deaths.4 5 The declining incidence of direct causes of maternal death has led to an increased awareness of nonobstetric factors such as stroke. Clearly, any recognised cause of stroke in young patients may also occur coincidentally during pregnancy, although there are a number of factors associated with pregnancy that have an important aetiological role, and these will be considered here. We will also consider the current scope of the problem, and focus on relevant areas unique to pregnancy, including issues surrounding investigation and treatment options.