A widespread multifocal or diffuse reduction in the caliber of the cerebral vessels and their branches constitutes a special syndrome of several causes. Vasospasm is, of course, a well-known complication of subarachnoid hemorrhage as described earlier. But the process under discussion has different characteristics. Some degree of attenuation of large cerebral vessels is observed in hypertensive encephalopathy and eclampsia as noted above, but a more diffuse and sustained reduction in vascular caliber can result from various causes summarized in Table 33-10. The main characteristics are severe headache, usually of the “thunderclap” variety as described in Chap. 9, and less prominently or frequently, fluctuating but sudden onset focal neurologic signs, seizures, or confusion that may progress to multifocal cerebral infarction, almost exclusively in the cerebral hemispheres. Women are affected more often than men. The identifying feature pointed out by Call et al is a striking widespread segmental vasospasm of cerebral vessels. The middle cerebral artery and its branches are mainly affected; the angiographic appearance may be mistaken for arteritis (Fig. 33-36).
There may be an associated posterior leukoencephalopathy or focal brain edema that is similar to the imaging appearance in hypertensive encephalopathy discussed just above. Sometimes the headache is minimal and the attenuation of vessels is found in imaging performed for other reasons. As in hypertensive encephalopathy, the spinal fluid, except perhaps for elevated pressure and occasionally red blood cells in quantities less than seen in rupture of berry aneurysm, is normal.
The patients we have seen with RCVS, after several days or weeks of dramatically fluctuating focal neurologic symptoms and disabling headache, have recovered completely or nearly so, but several have had small strokes. The longest recovery in our patients has taken 12 weeks in an idiopathic case. The syndrome is said to recur but two of our patients have had more than one attack, spaced years apart.
Many of our patients have had a history of migraine and the syndrome is often initially mistaken for a migraine attack. Series collected by others give an incidence of migraine of approximately 25 percent. This type of vasculopathy is produced by sympathomimetic drugs alone, such as ephedra in health food supplements, phenylpropanolamine, pseudoephedrine, methamphetamine, and cocaine, but there are few well-studied cases.
The cerebrovascular problems resulting from cocaine use are quite varied. Seizures and death may occur as a result of a syndrome of delirium and extreme hyperthermia. More pertinent to this chapter are the strokes that arise during and just after cocaine use. Here, as emphasized by Levine and colleagues (1991) many years ago, a distinction should be made between the complications of cocaine hydrochloride (the usual form of ingestible cocaine) and the alkaloid form, or “crack cocaine.” The former, when injected intravenously more so than when used intranasally, is prone to cause cerebral hemorrhage as a result of acute hypertension, similar to the bleeding that may be precipitated by other sympathomimetic drugs such as amphetamine and phenylpropanolamine. Both subarachnoid and intracerebral hemorrhage may result. Or, the features of hypertensive encephalopathy are precipitated, including changes in the posterior white matter of the cerebral hemispheres that are so striking on imaging studies (PRES, as discussed earlier). The strokes with crack cocaine, however, are more often ischemic, typically involving the territory of a large vessel. Some ambiguity attends the vasculopathy induced by crack cocaine, cocaine hydrochloride, and the amphetamines, particularly the first of these. There are undoubted instances of a true cerebral inflammatory vasculitis, perhaps of a hypersensitivity type such as those reported with biopsy verification by Krendel and colleagues, by Merkel and associates, and by others.