Thunderclap headache (TCH) is defined as a high-intensity headache with an abrupt onset, reaching its peak intensity within less than one minute and lasting for more than five minutes. This type of headache is usually indicative of serious underlying causes and is rarely a primary disorder. Here we are reporting an interesting case of thunderclap headache in an adolescent girlwho received a blood transfusion.
A 14 year old girl was admitted to our emergency department with a complaint of headache over the past two days that became unbearable in the last two hours before admission. She had two episodes of vomiting associated with transient blurring of vision of the lateral half of the left visual field.A neurological examination was unremarkable. Five days prior to this symptom, she was admitted with severe iron deficiency anemia(Hb-2.4 g%) and received four packed red blood cell transfusions on consecutive days. The interval between the last transfusion and the onset of the headache was 24 hours. An MRI brain showed focal subarachnoid hemorrhage with gradient looming and abnormal FLAIR hyperintensities in the right posterior temporal and occipital regions. An MR angiogram showed suspicious multifocal narrowing of the distal posterior cerebral artery (P4 branch), predominantly on the right side. No obvious aneurysm was noted. The MR venogram showed no evidence of cerebral venous thrombosis.The ECHO was normal. Two probable diagnoses were considered: Primary angiitis of the central nervous system (PACNS), and reversible cerebral vasoconstriction syndrome (RCVS). Laboratory investigations were negative for HIV, HbsAg, anti-HCV, ANA, ANCA. She was started on Nimodipine. A repeat MRI angiogram after 4 weeks showed improvement in stenotic areas in the vessels.
SWI and T2 FLAIR images showing blooming and Hyperintesities in Right Posterior Temporal and Occipital Region
Reversible Cerebral Vasoconstriction Syndrome
Reversible Cerebral Vasoconstriction Syndrome (RCVS) is a condition of vascular spasms in the brain, mainly presenting with a recurrent, severe, diffuse type of TCH that may be present or recurrent for 1 or 2 weeks from its onset and usually resolves within 3 months. This is a poorly understood condition, which can be associated with focal neurological deficits and seizures. The “string of beads” appearance on angiography, consisting of segmental vasodilations and vasoconstrictions, is the radiological characteristic of RCVS. RCVS and Subarachnoid Hemorrhage (SAH) are the most common causes of TCH, making it a medical emergency requiring immediate consideration. RCVS can be associated with Posterior Reversible Encephalopathy Syndrome (PRES) in severe cases. The major complications are localisedcortical subarachnoid haemorrhages (20–25%)and ischaemic or haemorrhagic strokes(5–10%). In contrast with the arterialabnormalities that are reversible within a fewweeks, these strokes may leave permanentsequelae and can even be fatal.
Reversible cerebral vasoconstriction syndrome has been reported in patients aged 13–70 years. The mean age of onset is around 45 years with a female to male preponderance from between about 2 and 10:1
Mechanisms and causes
Although the pathophysiology remainsunknown, the prevailing hypothesis is of atransient disturbance in the control ofcerebral vascular tone leading to segmentaland multifocal arterial constriction anddilatation. This disturbance may be spontaneous(so-called idiopathic reversible cerebralvasoconstriction syndrome), while 25–60% ofcases are secondary, mostly due to exposure tovasoactive sympathomimetic or serotoninergicsubstances, and/or to the postpartum state. It is important to emphasise that the headaches are secondary headaches, symptomatic of the vascular disorder; they have nothing to do with migraine which is a primary headache without any underlying causal lesion. A history of migraine is found in only 16–20% of reversible cerebral vasoconstriction syndrome cases, which is no different from the prevalence of migraine in the general population.
It is impossible to distinguish RCVS and PACNS based on angiographic features. Patients with RCVS may erroneouslybe treated as vasculitis, and may be exposedto long-term treatment by immunosuppressive agents withserious side effects. In the rare cases of persistent hesitationbetween the two diagnoses, it may be a good choice to waita few days with a calcium channel blocker (e.g., verapamil,nimodipine): RCVS is going to stabilize and improvequickly with regression of the vasoconstriction, and on thecontrary, arterial irregularities in PACNS are not going toimprove so fast. Heavy treatment with immunosuppressantsshould be reserved for patients having biopsy provenvasculitis. Consequently, in these patients, DSA should be repeated for definitive diagnosis.
RCVS associated with blood transfusion
Several complications are associated with the transfusion ofblood products, many of which can be grouped as immunologicalor infectious. However, neurologicalcomplications resulting from blood transfusion have been rarely reported. No reports exist of cases of RCVS that have resulted from transfused blood products in situations of acute blood loss.There is a theory that chronic anemia, accompanied by cerebral vasodilatation may occur to compensate for ischemic hypoxia. A loss of vasodilation and an increase in vascular resistance may be caused by a rapid increase in hemoglobin levels and viscosity during blood transfusions. This may cause overwhelming cerebral vessel constriction.
Symptomatic treatment includes analgesics(sometimes even morphine), antiepilepticdrugs for any seizures, monitoring bloodpressure, hospitalisation in an intensive careunit in severe cases, and, for all otherpatients, rest for a few days to a few weeksaccording to the severity of their headaches.Patients having triggered thunderclap headachesshould be advised to avoid the trigger,such as sexual activity and any other physical effort for 1 or 2 weeks. Finally, it is important to search for all possible vasoactive substances (repeated questioning is sometimes necessary), stop them and firmly suggest to the patient that he or she avoid these kinds of drugs and medications in the future. In the absence of any randomised trial, empirical treatment is based on nimodipine, started when the typical angiographic pattern is demonstrated. This may be given intravenously for a few days, in the same doses as for aneurysmal SAH (1–2 mg/kg/h with monitoring of blood pressure). More often, nimodipine is given orally, the dosevarying from 60 mg every 4–8 h, for 4–12 weeks.
In conclusion, RCVS was one of the complications resulting from a blood transfusion in patients with chronic severe anemia, in particular, in women with menorrhagia. RCVS should be considered in patients if they developed a severe headache or neurologic deficit after transfusion.
Dr. A. Sowmiya Rathnapratheep
2nd Year PG- DNB General Medicine