Eliana Mea

Vagus nerve stimulation in drug-resistant daily chronic migraine with depression: preliminary data

Drug refractory chronic daily headache (CDH) is a highly disabling condition. CDH is usually regarded as the negative evolution of chronic migraine (CM) and is characterized by high prevalence of psychiatric disorders, especially mood disorders. Vagal nerve stimulation (VNS) is an established treatment option for selected patients with medically refractory epilepsy and depression. Neurobiological similarities suggest that VNS could be useful in the treatment of drug-refractory CM associated with depression. The aim of the study was to evaluate the efficacy of VNS in patients suffering from drug-refractory CM and depressive disorder. We selected four female patients, mean age 53 (range 43–65 years), suffering from daily headache and drug-refractory CM. Neurological examination and neuroradiological investigations were unremarkable. Exclusion criteria were psychosis, heart and lung diseases. The preliminary results in our small case series support a beneficial effect of chronic VNS on both drug-refractory CM and depression, and suggest this novel treatment as a valid alternative for this otherwise intractable and highly disabling condition.

Acute hypothalamic stimulation and ongoing cluster headache attacks

Long-term hypothalamic stimulation is effective in improving drug-resistant chronic cluster headache (CH). We assessed acute hypothalamic stimulation to resolve ongoing CH attacks in 16 patients implanted to prevent chronic CH, investigating 136 attacks. A pain intensity reduction of ≥50% occurred in 25 of 108 evaluable attacks (23.1%). Acute hypothalamic stimulation is not effective in resolving ongoing CH attacks, suggesting that hypothalamic stimulation acts by complex mechanisms in CH prevention.

Headache and intracranial hypotension: neuroradiological findings

Abstract.The cardinal and classic features of postural headache and low cerebrospinal fluid (CSF) pressure in intracranial hypotension may not dominate the clinical picture of the syndrome and may be associated with additional various neurological symptoms and signs. Reports of unusual clinical presentations continue to appear in the literature. Despite the considerable variability of the clinical spectrum, neuroradiological studies reveal more constant and characteristic features. Brain MRI findings include intracranial pachymeningeal thickening and post-contrast enhancement, subdural fluid collections and downward displacement or “sagging” of the brain. Spinal MRI findings include collapse of the dural sac with a festooned appearance, intense epidural enhancement owing to dilatation of the epidural venous plexus, and possible epidural fluid collections. In fact, spinal studies may demonstrate CSF leakage from spinal dural defects, which are considered the most common cause of the syndrome. Myelo-MR may suggest the possible point of CSF leakage, by demonstrating an irregular root sleeve; myelo-CT and radioisotope myelocisternography (RMC) are often needed to confirm the point of CSF leakage. Neuroimaging studies are, therefore, essential for suggesting and confirming the diagnosis.

Deep brain stimulation and cluster headache.

In recent years, neuroimaging data have greatly improved the knowledge on trigeminal autonomic cephalalgias’ (TACs) central mechanisms. Positron emission tomography studies have shown that the posterior inferior hypothalamic grey matter is activated during cluster headache attacks as well as in short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT). Voxel-based morphometric MRI has also documented alteration in the same area in cluster headache patients. These data suggest that the cluster headache generator is located in this region and leads us to hypothesise that stimulation of this brain area could relieve intractable cluster headache just as deep brain stimulation improves intractable movements disorders. This view received support by the observation that high frequency stimulation of the ipsilateral hypothalamus prevented attacks in an otherwise intractable chronic cluster headache patient previously treated unsuccessfully by surgical procedures to the trigeminal nerve. So far, 16 patients with intractable cronic cluster headache (CCH) and one intractable SUNCT patient have been successfully treated by hypothalamic stimulation. The procedures were well tolerated with no significant adverse events. Hypothalamic DBS is an efficacious and safe procedure to relieve otherwise intractable CCH and SUNCT.

Dural sinus thrombosis in spontaneous intracranial hypotension : Hypotheses on possible mechanisms

Dural sinus thrombosis (DST) is rarely associated with spontaneous intracranial hypotension (SIH). Engorgement of the venous system, caused by the CSF loss that occurs in SIH, is considered to favour the thrombosis, although signs of both SIH and DST are usually seen simultaneously at the first diagnostic MRI. We observed two patients with SIH and DST. Changes in pattern of headaches and MRI findings demonstrated that DST followed SIH. In SIH, the velocity of the blood flow in the dural sinuses may be reduced because of dilatation of the venous system which compensates the CSF loss. Other possible mechanisms seem unlikely on the grounds of both clinical presentation and MRI studies.

Hypothalamic deep-brain stimulation modulates thermal sensitivity and pain thresholds in cluster headache

ABSTRACT Deep‐brain stimulation (DBS) of the posterior hypothalamus has been shown to be clinically effective for drug‐resistant chronic cluster headache, but the underlying mechanism is still not understood. The hypothalamus as an important centre of homeostasis is connected among others to the trigeminal system via the trigeminohypothalamic tract. We aimed to elucidate whether hypothalamic stimulation affects thermal sensation and pain perception only in the clinically affected region (the first trigeminal branch) or in other regions as well. Thus, we examined three groups: chronic cluster headache patients with unilateral DBS of the posterior hypothalamus (n = 11), chronic cluster headache patients without DBS (n = 15) and healthy controls (n = 29). Perception and pain thresholds for hot and cold stimuli were determined bilaterally in all subjects supraorbitally, at the forearm, and in the lower leg. In DBS patients, thresholds were determined with the stimulator activated and inactivated. Cold pain thresholds at the first trigeminal branch were increased on the stimulated side in the DBS group compared to healthy subjects (p = .015). The DBS group also had higher cold detection thresholds compared to non‐implanted cluster headache patients (p < .05). Short‐term interruption of stimulation did not induce any changes in DBS patients. Clinically relevant differences were found neither between non‐stimulated cluster headache patients and healthy controls nor between the affected and the non‐affected sides in the chronic cluster headache patients without DBS. These results support the notion that neurostimulation of the posterior hypothalamus is specific for cluster headache and only affects certain aspects of pain sensation.

Neuroimaging and pain: a window on the autonomic nervous system.

Pain is one of the most common experiences of humans. Neuroimaging techniques can visualize the main brain areas involved in pain modulation, the pain matrix. It is noteworthy that many of the brain areas forming the pain matrix are also involved in modulating autonomic nervous system (ANS) activity that in turn plays a major role in determining the best adaptive response to the pain experience. The tight connection between the pain system and ANS is also evident from neuroanatomical studies indicating that the lamina 1 neurons receive both painful and visceral stimuli from all visceral organs giving rise to the spinothalamocortical pathway concerned with conveying interoceptive information to central structures. The resulting interoceptive stream projects to the viscerosensory cortex in the mid-insula and onto the right anterior insula and orbitofrontal cortices. Right anterior insula activation is involved in the sympathetic arousal associated with mental tasks. This brain region receives numerous other inputs including pain and painful stimuli are conveyed somatotopically to both insulae. A similar somatotopic organization of painful stimuli has also been shown in the basal ganglia involved in cognitive, affective, motor and autonomic states. This highly specialized organization of nociceptive information in these brain areas may subserve a number of functions, particularly of coupling pain with the most appropriate autonomic states and affective/emotional states. The anterior cingulated cortex, another brain area playing a crucial role in nociception, is also directly involved in the control of autonomic functions such as arousal during volitional behaviour, including effortful cognitive processing. It is evident that the nociceptive system and ANS closely interact in many processes involved in maintaining internal homeostatis and in order to give the most appropriate biological substrate for cognitive, affective and emotional states.

Coexistence of TACS and Trigeminal Neuralgia: Pathophysiological Conjectures

Background.—Trigeminal autonomic cephalgias (TACs) and trigeminal neuralgia are short‐lasting unilateral primary headaches whose study is providing insights into craniofacial pain mechanisms. We report on 2 patients in whom trigeminal neuralgia coexists with the TACs paroxysmal hemicrania and SUNCT.

Deep brain stimulation in trigeminal autonomic cephalalgias

SummaryCluster headache (CH), paroxysmal hemicrania (PH), and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT syndrome) are primary headaches grouped together as trigeminal autonomic cephalalgias (TACs). All are characterized by short-lived unilateral head pain attacks associated with oculofacial autonomic phenomena. Neuroimaging studies have demonstrated that the posterior hypothalamus is activated during attacks, implicating hypothalamic hyperactivity in TAC pathophysiology and suggesting stimulation of the ipsilateral posterior hypothalamus as a means of preventing intractable CH. After almost 10 years of experience, hypothalamic stimulation has proved successful in preventing pain attacks in approximately 60% of the 58 documented chronic drug-resistant CH patients implanted at various centers. Positive results have also been reported in drug-resistant SUNCT and PH. Microrecording studies on hypothalamic neurons are increasingly being performed and promise to make it possible to more precisely identify the target site. The implantation procedure has generally proved safe, although it carries a small risk of brain hemorrhage. Long-term stimulation is proving to be safe: studies on patients under continuous hypothalamic stimulation have identified nonsymptomatic impairment of orthostatic adaptation as the only noteworthy change. Studies on pain threshold in chronically stimulated patients show increased threshold for cold pain in the distribution of the first trigeminal branch ipsilateral to stimulation. When the stimulator is switched off, changes in sensory and pain thresholds do not occur immediately, indicating that long-term hypothalamic stimulation is necessary to produce sensory and nociceptive changes, as also indicated by clinical experience that CH attacks are brought under control only after weeks of stimulation. Infection, transient loss of consciousness, and micturition syncope have been reported, but treatment interruption usually is not required.

Psychopathological profile of patients with chronic migraine and medication overuse: Study and findings in 50 cases

Patients with chronic migraine (CM) have high frequence of psychiatric comorbidity or psychological distress. The presence of depression, anxiety, panic or obsessive disorders in these patients contributes to poor quality of life and can influence prognosis and treatment. A systematic investigation of psychiatric comorbidity is needed in patients with CM especially in those with medication overuse (MO), in order to reach a more comprehensive clinical management. We assessed the psychological profile of 50 patients, 40 women and 10 men suffering from CM with MO. The Spectrum Project, a complementary way of describing and assessing psychopathology with structured clinical interviews, was used for the psychological evaluation of the patients to explore personality traits. Spectrum instruments mood disorders (MOODS), panic agoraphobic disorders (PAS) and obsessive–compulsive disorder (OBS) were applied to study patients. OBS-questionnaire was positive in 28% of the patients, MOODS-questionnaire in 44%, PAS-questionnaire in 46%. 19 on 50 patients (38%) presented positivity to 2 or to all questionnaires in variable associations. None of the patients of the studied group had complete normal findings in the questionnaires. Clinical records of patients with OBS-questionnaire positivity showed a worse clinical course and tendency to relapse. These results suggest that psychological assessment is an essential step in the evaluation and treatment of patients with CM and MO. The remarkable percentage of OBS-questionnaire positivity in this group indicates that obsessive–compulsive trait represents besides depression and anxiety, a major risk of chronification and overusing.