Extensive splanchnic vein thrombosis after SARS-CoV-2 vaccination: A Vascular Liver Disease Group (VALDIG) initiative

BACKGROUND AND AIMS

Since the introduction of SARS-CoV-2 vaccines, several cases of vaccine-induced immune thrombocytopenia and thrombosis (VITT) have been described, especially cerebral vein thrombosis. We aimed to retrospectively collect all new cases of acute onset first or recurrent splanchnic vein thrombosis (SVT) following a recent SARS-CoV-2 vaccination within the Vascular Liver Disease Group network.

APPROACH AND RESULTS

New cases of SVT were identified from April 2021 to April 2022; follow-up was completed on December 31, 2022. Criteria to define VITT were derived from previous studies. Data from a pre-COVID cohort of patients with SVT (N=436) were used for comparison of clinical presentation, etiology, and outcome. Twenty-nine patients were identified with SVT occurring with a median of 11 days (range 2-76) after the first (48%), second (41%), or third (10%) vaccination (ChAdOx1 nCov-19 (n=12) or BNT162b2 (n=14), other (n=3) Only 2 patients(7%) fulfilled criteria for definite VITT. Twenty (69%) had SVT at multiple sites, including 4 (14%) with concomitant extra-abdominal thrombosis. Only 28% had an underlying prothrombotic condition, compared to 52% in the pre-COVID SVT cohort ( p =0.01). Five patients (17%) underwent bowel resection for mesenteric ischemia, compared with 3% in pre-COVID SVT ( p <0.001). Two patients died shortly after diagnosis (7%).

CONCLUSIONS

Although definite VITT was rare, in 72% of cases, no other cause for SVT could be identified following SARS-CoV-2 vaccination. These cases were different from patients with nonvaccine-related SVT, with lower incidence of prothrombotic conditions, higher rates of bowel ischemia, and poorer outcome. Although SVT after SARS-CoV-2 vaccination is rare in absolute terms, these data remain relevant considering ongoing revaccination programs.

Correlation between neuroimaging, neurological phenotype, and functional outcomes in Wilson's disease

INTRODUCTION

Wilson's disease (WD) is associated with a variety of movement disorders and progressive neurological dysfunction. The aim of this study was to correlate baseline brain magnetic resonance imaging (MRI) features with clinical phenotype and long-term outcomes in chronically treated WD patients.

METHODS

Patients were retrospectively selected from an institutional database. Two experienced neuroradiologists reviewed baseline brain MRI. Functional assessment was performed using the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) scale, and disease severity was classified using the Global Assessment Scale for Wilson's Disease (GASWD).

RESULTS

Of 27 patients selected, 14 were female (51.9%), with a mean (standard deviation [SD]) age at onset of 19.5 (7.1) years. Neurological symptoms developed in 22 patients (81.5%), with hyperkinetic symptoms being the most common (70.4%). Baseline brain MRI showed abnormal findings in 18 cases (66.7%), including T2 hyperintensities in 59.3% and atrophy in 29.6%. After a mean (SD) follow-up of 20.9 (11.0) years, WD patients had a mean score of 19.2 (10.2) on WHODAS 2.0 and 6.4 (5.7) on GASWD. The presence of hyperkinetic symptoms correlated with putaminal T2 hyperintensities (p = 0.003), putaminal T2 hypointensities (p = 0.009), and mesencephalic T2 hyperintensities (p = 0.009). Increased functional disability was associated with brain atrophy (p = 0.007), diffusion abnormalities (p = 0.013), and burden of T2 hyperintensities (p = 0.002). A stepwise regression model identified atrophy as a predictor of increased WHODAS 2.0 (p = 0.023) and GASWD (p = 0.007) scores.

CONCLUSIONS

Atrophy and, to a lesser extent, deep T2 hyperintensity are associated with functional disability and disease severity in long-term follow-up of WD patients.

Liver Transplantation for Porto-sinusoidal Vascular Liver Disorder: Long-term Outcome

BACKGROUND

Porto-sinusoidal vascular liver disorder (PSVD) is a rare disease that occasionally requires liver transplantation (LT), despite usually presenting preserved liver function. There remains a paucity of data pertaining to LT in PSVD. The aim was to identify features associated with post-LT outcomes in PSVD.

METHODS

Retrospective multicentre study of 79 patients who received LT for PSVD.

RESULTS

Median post-LT follow-up was 37 (range 1-261) mo. Refractory ascites 24 (30%), hepatic encephalopathy 16 (20%), and hepatopulmonary syndrome 13 (16.3%) were the most frequent indications for LT. Hepatocellular carcinoma was the indication in only 2 patients. Twenty-four patients died, 7 due to liver and 17 to non-liver related causes. Post-LT survival was 82.2%, 80.7%, and 68.6% at 1, 2, and 5 y, respectively. Post-LT survival was significantly better in patients without (n = 58) than in those with a persistent severe PSVD-associated condition (n = 21). Pre-LT hyperbilirubinemia levels and creatinine >100 µmol/L were also independently associated with poor survival. Six patients (7.6%) required a second LT. Recurrence of PSVD was confirmed by liver biopsy in only 1 patient and in 3 further patients it was likely.

CONCLUSIONS

LT in PSVD is associated with an acceptable outcome in the absence of associated severe conditions. However, persistence of a severe associated condition, pre-LT high bilirubin levels, or creatinine >100 µmol/L impact outcome, and these are features that should be considered when evaluating PSVD patients for LT. PSVD recurrence is possible after LT and needs to be explored, at least, in cases of posttransplant portal hypertension.

Ethics in Authorship: Considerations and Concerns

N/a.

The Role of a Medical Intermediate Care Unit in the Management of Budd-Chiari Syndrome: Case Series

Budd-Chiari syndrome (BCS) has a wide spectrum of presentations, from an asymptomatic status to acute liver failure (ALF). The therapeutic approach depends on disease severity and related etiology with patients with severe forms of presentation classically managed in intensive care units (ICUs). Here, we report a series of five BCS patients managed in a medical intermediate care unit (IntCU), with three of them presenting with acute liver injury. Progression to ALF was seen in three patients, two of whom died, with one being successfully submitted to liver transplantation. IntCUs allow a 24-h patient surveillance and a prompt management of BCS, with less economic impact when compared to ICUs. Mortality was related to the presence of associated comorbidities that limited therapeutic approach.

Dorfman-Chanarin Syndrome: A Rare Cause of Metabolic Associated Fatty Liver Disease Related to Homozygosity of the Nonsense Mutation c.934C&#x3e;T (p.R312*)

Metabolic associated fatty liver disease became the most common form of chronic liver disease, in the vast majority of the cases related to increased insulin resistance or metabolic dysregulation. Yet, other causes may be implied. We report the late diagnosis of Dorfman-Chanarin syndrome in a non-alcoholic steatohepatitis previously labeled cirrhotic middle-aged man, with consanguineous parents, complicated with hepatocellular carcinoma. Congenital ichthyosis, neurosensory hearing loss and elevated muscular enzymes hit on the track of Dorfman-Chanarin syndrome. The genetic analysis uncovered a first-time described homozygotic nonsense mutation in the ABHD5 gene, responsible for coding the ABHD5 protein. The patient was successfully submitted to liver transplantation. Inborn errors of metabolism are a rare cause of metabolic associated fatty liver disease, but they need to be kept in consideration in all patients who present with atypical clinical features. This shall raise the awareness of physicians to rare forms of presentation since it may imply not only a different prognosis, but also other actions, like particular therapies as liver transplantation due to related complications of cirrhosis, or familial screening.

Budd-Chiari Syndrome and Acute Liver Failure: An Uncommon Presentation of Acute Myeloid Leukaemia

Acute liver failure (ALF) is a rare entity, particularly in the context of Budd-Chiari syndrome (BCS). BCS is an uncommon disorder with multiple risk factors, most commonly myeloproliferative disorders. In BCS, active search and exclusion of underlying malignancy is mandatory, particularly in the context of ALF, as it may contraindicate liver transplantation (LT). We present the case of a healthy 29-year-old male, without known risk factors for liver disease, who presented to the emergency department with abdominal pain, ascites, and jaundice. BCS with consequent severe acute liver injury with rapid progression to ALF was diagnosed. The patient was listed for LT. The study of peripheral blood finally revealed myeloid blasts, and flow cytometry showed a population of blast cells with abnormal immunophenotypic profile (CD33+ and myeloperoxidase, MPO+). The bone marrow biopsy showed morphological and immunophenotypic aspects of acute myeloid leukaemia (AML) FAB M1. This diagnosis was considered a formal contraindication to LT, so the patient was delisted. ALF contraindicated rescue chemotherapy and AML contraindicated LT. The patient died 48 h after ICU admission. The search for underlying neoplasia is mandatory in the context of BCS, moreover with associated ALF, as it may limit lifesaving treatments and interventions to supportive and palliative care.

Porto-sinusoidal vascular disease: proposal and description of a novel entity

Portal hypertension in the absence of portal vein thrombosis and without cirrhosis, but with mild or moderate alterations of liver histology (eg, obliterative venopathy, nodular regenerative hyperplasia, or incomplete septal cirrhosis) is being increasingly recognised. Owing to the heterogeneity of causes and histological findings, a substantial number of terms have been used to describe such idiopathic non-cirrhotic portal hypertension. Patients with the same clinical and histological features exist, but without portal hypertension at the time of diagnosis. Therefore, improved criteria are needed to define this form of liver disease. Here, we propose the term porto-sinusoidal vascular disease, since all lesions found involve the portal venules or sinusoids. The definition of this entity is based on the characteristic absence of cirrhosis with or without signs of portal hypertension or histological lesions. The presence of known causes of liver disease does not rule out porto-sinusoidal vascular disease, but specific causes of vascular liver disease are excluded from its definition. The diagnosis of porto-sinusoidal vascular disease is based on liver biopsy and might include signs specific for portal hypertension with normal or mildly elevated liver stiffness values and no complete portal vein thrombosis. We provide simple diagnostic criteria, because agreement on a uniform nomenclature is an essential requirement for future collaborative studies.

Improvement of Central Nervous System Vasculitis in a Patient with Chronic Hepatitis C Virus Infection after Treatment with an Interferon-Free Regimen

BACKGROUND

Neurosarcoidosis is a rare manifestation of hepatitis C virus (HCV) infection, mainly in patients exposed to interferon-based therapies. Although we are living in a new era of HCV treatment, there is still little data concerning the treatment of extrahepatic complications of the disease with direct antiviral agents, especially rare ones such as neurosarcoidosis.

SUMMARY

We present a rare case of central nervous system vasculitic lesions in the context of chronic HCV infection associated with mixed cryoglobulinemia, elevated angiotensin-converting enzyme (ACE) levels, and documentation of viral RNA in the cerebrospinal fluid in a treatment-naïve chronic HCV patient. Successful treatment with an interferon-free regimen improved all clinical manifestations, reduced the levels of serum ACE, and reduced the cryoglobulin levels to undetectable.

MESSAGES

Neurosarcoidosis and cryoglobulinemia are rare but well-recognized complications of HCV infection, even in treatment-naïve patients. Direct antiviral agents can be useful in the management of this condition.

Nonselective beta-blockers and the risk of portal vein thrombosis in patients with cirrhosis: results of a prospective longitudinal study

BACKGROUND

Nonmalignant portal vein thrombosis is a significant event in the course of cirrhosis that can contraindicate liver transplantation and even impact survival after the surgical procedure. Risk factors are not completely known or validated and are still debated.

AIM

To identify in patients with cirrhosis the risk factors for portal vein thrombosis that are assessable in clinical practice.

METHODS

Between January 2014 and February 2017, 108 outpatients with cirrhosis and no portal vein thrombosis (78% Child A) were enrolled. Doppler ultrasound was performed every 3 or 6 months, for a median follow up of 19 months.

RESULTS

Portal vein thrombosis developed in 11 patients. Nonselective beta-blockade (hazard ratio [HR] 10.56; 95% confidence interval [CI]: 1.35-82.73; P = 0.025), and medium or large-sized oesophageal varices (HR 5.67; 95% CI: 1.49-21.63; P = 0.011) at baseline were associated with portal vein thrombosis development. Although heart rate (P < 0.001) and portal blood flow velocity at baseline (P = 0.005) were significantly reduced by nonselective beta-blockers, they were not related to portal vein thrombosis development.

CONCLUSIONS

Our findings confirm an association between portal vein thrombosis development and oesophageal varices at baseline, but suggest that the association could be explained by exposure to nonselective beta-blockers, independently from effects on heart rate and portal blood flow velocity. The mechanisms that explain portal vein thrombosis development in patients on nonselective beta-blockers require elucidation in order to optimise targeting of nonselective beta-blockade in patients with cirrhosis.

Antithrombotic treatment with direct-acting oral anticoagulants in patients with splanchnic vein thrombosis and cirrhosis

BACKGROUND

Direct-acting oral anticoagulants (DOACs) are used in patients with splanchnic vein thrombosis (SVT) and cirrhosis, but evidence for safety and efficacy in this setting is limited. Our aim was to identify indications and reasons for starting or switching to DOACs and to report adverse effects, complications and short-term outcome.

METHODS

Data collection including demographic information, laboratory values, treatment and complications through the Vascular Liver Disease Interest Group Consortium.

RESULTS

Forty-five centres (90%) of the consortium completed the initial eCRF. We report here a series of 94 patients from 17 centres. Thirty-six patients (38%) had cirrhosis. Child-Pugh score was 6 (range 5-8), and MELD score 10.2 (range 6-19). Indications for anticoagulation were splanchnic vein thrombosis (75%), deep vein thrombosis (5%), atrial fibrillation (14%) and others (6%). DOACs used were rivaroxaban (83%), dabigatran (11%) and apixaban (6%). Patients were followed up for a median duration of 15 months (cirrhotic) and 26.5 months (non-cirrhotic). Adverse events occurred in 17% of patients and included one case of recurrent portal vein thrombosis and five cases of bleeding. Treatment with DOACs was stopped in three cases. The major reasons for choosing DOACs were no need for monitoring or inadequacy of INR to guide anticoagulation in cirrhotic patients. Renal and liver function did not change during treatment.

CONCLUSIONS

A consistent number of patients with SVT and/or cirrhosis are currently treated with DOACs, which seem to be effective and safe. These data provide a basis for performing randomized clinical trials of DOACs vs. low molecular weight heparin or vitamin K antagonists.

Efficacy and Safety of Direct-Acting Oral Anticoagulants Use in Acute Portal Vein Thrombosis Unrelated to Cirrhosis

In acute portal vein thrombosis (APVT) unrelated to cirrhosis, anticoagulant therapy is classically started with low molecular weight heparin or vitamin K antagonists. New direct-acting oral anticoagulants (DOACs) are used in the treatment of venous thrombosis outside the splanchnic vascular bed, but not in the latter. We report a young female with APVT occurring in a non-cirrhotic liver linked to heterozygosity of factor V-Leiden and prothrombin G20210A gene mutations. Rivaroxaban was started, with total recanalization of the left and partial recanalization of the right portal vein branches, without complications. New DOACs do not need daily subcutaneous injections nor routinely blood coagulation control tests, making its use attractive, eventually increasing patient’s compliance. If proved to be safe and effective in the future studies, its use may be extended to PVT treatment. This case shows that rivaroxaban was safe, not only prevented the extension of thrombosis in the portal tract, but also resolved PVT, at least partially.

Causes and consequences of portal vein thrombosis in 1,243 patients with cirrhosis: results of a longitudinal study

In cirrhosis, portal vein thrombosis (PVT) could be a cause or a consequence of the progression of liver disease. We analyzed data from a prospective trial of ultrasound screening for hepatocellular carcinoma in order to identify risk factors for and the impact of PVT in patients with cirrhosis. In all, 1,243 adults with cirrhosis without PVT were enrolled from 43 liver units in France and Belgium between June 2000 and March 2006. The mean follow-up was 47 months. Doppler ultrasonography was used to check the portal vein. Progression of liver disease was defined by the development of: ascites, hepatic encephalopathy, variceal bleeding, prothrombin <45%, serum bilirubin >45 μmol/L, albumin <28 g/L, and/or creatinine >115 μmol/L. G20210A prothrombin and factor V gene mutations were assessed in sera stored at three large centers. The 5-year cumulative incidence of PVT was 10.7%. PVT was mostly partial and varied over time. The development of PVT was independently associated with baseline esophageal varices (P = 0.01) and prothrombin time (P = 0.002), but not with disease progression before PVT, or prothrombotic mutations. Disease progression was independently associated with baseline age (hazard ratio [HR] 1.55; 95% confidence interval [CI]: 1.11-2.17), body mass index (HR 1.40; 95% CI: 1.01-1.95), prothrombin time (HR 0.79; 95% CI: 0.70-0.90), serum albumin (HR 0.97; 95% CI: 0.94-0.99), and esophageal varices (HR 1.70; 95% CI: 1.21-2.38) but not with the prior development of PVT (HR 1.32; 95% CI: 0.68-2.65).

CONCLUSION

In patients with cirrhosis, the development of PVT is associated with the severity of liver disease at baseline, but does not follow a recent progression of liver disease. There is no evidence that the development of PVT is responsible for further progression of liver disease.

From Clinical Presentation to the Outcome: the Natural History of PML in a Portuguese Population of HIV Infected Patients

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system, associated with immunosuppression states. As there are only some non-published documents concerning PML in HIV infected patients in Portugal, we pretend to characterize natural history of PML infection in a population of HIV patients.

METHODS

We retrospectively reviewed, from 1992 to 2009, PML cases in a population of 724 HIV infected patients followed in our institution. Clinical, biological, imagery features and outcomes were characterized.

RESULTS

Twenty-five (3.45%) patients were identified as having PML. The mean time between HIV and PML diagnosis was 20.4 months. PML was the presentation of HIV infection in 40% of the patients, and 92% had CD4 T cell count lower than 200/mm(3). Paresis was the most common clinical presentation. No specific characteristics were found in cerebrospinal fluid and JCV DNA was positive in 3 of 7 patients. MRI revealed characteristic findings. Combined antiretroviral therapy was started or changed in 96% of the patients. Neurological condition got worse in 12 patients. From the 14 deaths, 5 were directly attributed to PML progression. Follow-up was lost in 8 patients.

CONCLUSIONS

PML was the presentation of HIV infection in more than 1/3 of patients, frequently associated with advanced immunocompromise. MRI sensitivity to PML is high, and JCV DNA determination in CSF was not revealed to be sensible. PML diagnosis should be taken into account in HIV patients presenting any neurological symptoms, and HIV infection should be suspected when radiological findings suggest PML lesions even in previously healthy individuals.

KEYWORDS

Progressive multifocal leukoencephalopathy; JC virus; Human immunodeficiency virus; Demyelinating disease.

Tartrate-resistant acid phosphatase as a biomarker of bone turnover in dog

Values of serum tartrate-resistant acid phosphatase ( TRAP) activity were obtained in adult dogs and its biological variability was assessed. Nine healthy skeletally mature Portuguese Podengo dogs were used for the determination of TRAP, total and bone alkaline phosphatase serum activities, and also to study their relationship with serum minerals, namely calcium (Ca), phosphorous (P), and magnesium (Mg). The serum TRAP activity was 2.19±0.56IU/mL, with intra-individual variation of 18.3% and inter-individual variation of 25.6%. Significant correlations were observed between serum TRAP activity and Ca (r=-0.3431; P<0.05), Ca and Mg (r=-0.787; P<0.01), and TRAP and Mg (r=0.397; P<0.05). The results indicate that serum TRAP activity in dog could be of great value in research and in clinical practice, providing complementary non-invasive information on bone metabolism

Twelve Years of Experience in the Management of Testicular Germ Cell Tumors at a Referral Center in Portugal

Background

Testicular germ cell tumors (TGCT) are generally rare but quite frequent in young males. Guidelines are well established for their management.

Methods

We present the first report from Portugal on clinical, histological, treatment modalities and outcomes of a population with TGCT. Data was retrospectively analyzed for the 1996 through 2008 period, applying a previous internally validated protocol.

Results

Seventy nine patients with TGCT were identified, 40.5% had seminomatous and 59.5% nonseminomatous tumors. Incidence rates were higher among males in their twenties and thirties. Pain and swelling testis were the most common symptoms and microlithiasis was detected in 20.3% of patients. Lower stages were more frequent in seminomatous tumors. Orchiectomy was done in all patients and further therapy was performed by guidelines recommendations in 86.1% of them. Hematological toxicity was found in 44.3% of the population studied and free disease survival rates were at 88.6%.

Conclusions

This retrospective study corroborates the European Western country trends concerning TGCT. Mortality was only seen in nonseminomatous TGCT group. Good risk and lower TGCT stages have no deaths reported. Public health campaigns should be undertaken to guide patients to seek medical advice earlier in the course of the disease.

Sorafenib Improves Survival in Metastatic Hepatocellular Carcinoma: A Case Report

Hepatocellular carcinoma (HCC) is a very common cancer. Curative treatments and local ones are well validated. Sorafenib, a multi-kinase receptor inhibitor was introduced in 2007 for advanced HCC in patients with preserved liver function. HCC is known to be resistant to systemic chemotherapy, and there are no validated therapies improving survival for metastatic disease. Herein, we report a case of a 45 years old woman with chronic hepatitis B infection submitted to a right hepatectomy in May 2001 for an hepatic tumor with more than 10 cm wide, confirmed as a HCC moderately differentiated. Three years later, a solitary pulmonary metastasis was documented and a metastectomy was done. In February 2009, the patient started on sorafenib 400 mg twice daily due to an inferior mediastinal metastasis with a vena cava thrombus associated. Computed tomography (CT) scan done 13 months after revealed a consistently mass reduction in more than 50% and a clinically well patient without important collateral effects. HCC is a highly vascularized tumor and sorafenib is known to inhibit both tumor angiogenesis and tumor cell survival. It is already approved for the treatment of advanced and metastatic renal cell cancer. In our case, the combination of two well done surgical procedures and the posterior use of sorafenib when a metastasis was found in an inaccessible surgical place with macroscopic vascular invasion, led to a long survival without important side effects.

Metachronous Testicular Germ-cell Tumors: The Importance of a Long-Term Follow-up

Testicular germ cell tumors (TGCT) are the most common malignancy in young male adults. They can be bilateral, and occur as a synchronous or metachronous tumor. The authors intend to characterize the prevalence and outcome of metachronous TGCT in the last 12 years of experience at our center. Cancer data base of our center was reviewed in order to find the patients that had TGCT in the period between 1996 and 2008 and, among those, the patients that had a second malignancy in the contralateral testicle after at least 6 months apart. Risk factors, clinical presentation, histological characteristics, staging, therapy and outcome were considered. Two out of 79 patients had metachronous TGCT, representing 2.5% of the group. Both cases had a low stage malignancy at the time of the diagnosis of the first tumor, and the diagnosis of the second TGCT happened 7 and 12 years later. Both patients are still alive without evidence of residual disease, under androgen replacement therapy and with testicular bilateral prostheses. Sperm cryopreservation was done in one of the patients. Long-term surveillance for TGCT is needed due to the probability of a second malignancy after the first 5 years of normal follow up. Special consideration must be given to patients submitted to bilateral orchiectomy concerning sperm cryopreservation, androgen replacement therapy and testicular prostheses.

Familial clusters of ANCA small-vessel vasculitis

Small-vessel vasculitides associated with the presence of antineutrophil cytoplasmic antibodies in the serum are characterized by inflammation and necrosis of small vessels. A pauci-immune necrotizing crescentic glomerulonephritis typically occurs when there is renal damage. Pathogenesis of these diseases remains unclear although infectious, genetic and environmental factors have been involved. Few familial clusters of antineutrophil cytoplasmic antibodies' small-vessel vasculitis are described in the literature. We report two families with first-degree relatives affected with antineutrophil cytoplasmic antibodies' small-vessel vasculitis.

Adjunctive zonisamide for treatment refractory anxiety

The aim of the study was to assess the use of a novel anticonvulsant, zonisamide, in patients with treatment refractory anxiety. Pilot and open study of a cohort of patients with anxiety (n = 10), who were deemed partial or non-responders to anxiolytic therapy, and received adjunctive zonisamide in a naturalistic fashion. The primary outcome measures were the Hamilton Anxiety Scale (HAM-A), the Clinical Global Impression of Severity (CGI-S) and the Clinical Global Impression of Improvement (CGI-I). Patients included were markedly ill with a mean number of previous medication trials of 4.9 +/- 1.9, a baseline HAM-A score of 27.9 +/- 3.8, and a baseline CGI-S score of 5.7 +/- 0.5. Patients improved significantly with an end-point HAM-A score of 12.6 +/- 7.4 (p < 0.001), CGI-S score of 3.6 +/- 1.3 (p < 0.002) and CGI-I score of 2.5 +/- 1.3. Zonisamide at a mean +/- SD dose of 160 +/- 70 mg/day for 9.2 +/- 4.5 weeks was generally well tolerated. Adverse events were generally mild, and no patients discontinued zonisamide because of side effects. Six patients (60%) met responder criteria at end-point (CGI-I <or= 2). Results from this pilot and open naturalistic study suggest that zonisamide may effectively augment response to anxiolytic medications in patients with treatment refractory anxiety. Larger and controlled studies are warranted to confirm these preliminary findings.