Intracranial cysts in autosomal dominant polycystic kidney disease

Familial and syndromic forms of arachnoid cyst implicate genetic factors in disease pathogenesis

Arachnoid cysts (ACs) are the most common space-occupying lesions in the human brain and present significant challenges for clinical management. While most cases of ACs are sporadic, nearly 40 familial forms have been reported. Moreover, ACs are seen with increased frequency in multiple Mendelian syndromes, including Chudley-McCullough syndrome, acrocallosal syndrome, and autosomal recessive primary ciliary dyskinesia. These findings suggest that genetic factors contribute to AC pathogenesis. However, traditional linkage and segregation approaches have been limited in their ability to identify causative genes for ACs because the disease is genetically heterogeneous and often presents asymptomatically and sporadically. Here, we comprehensively review theories of AC pathogenesis, the genetic evidence for AC formation, and discuss a different approach to AC genomics that could help elucidate this perplexing lesion and shed light on the associated neurodevelopmental phenotypes seen in a significant subset of these patients.

PKD1-Associated Arachnoid Cysts in Autosomal Dominant Polycystic Kidney Disease

OBJECTIVES

the prevalence of intracranial aneurysms and arachnoid cysts is higher in patients with autosomal dominant polycystic kidney disease (ADPKD) than in the general population. A genotype correlation was reported for intracranial aneurysms, but it is unclear for arachnoid cysts. Therefore, the genotype correlation with intracranial aneurysms and arachnoid cysts was investigated in ADPKD.

MATERIALS AND METHODS

intracranial aneurysms and arachnoid cysts were screened by magnetic resonance imaging (MRI), and PKD genotypes were examined using next-generation sequencing for 169 patients with ADPKD.

RESULTS

PKD1-, PKD2- and no-mutation were identified in 137, 24 and 8 patients, respectively. Intracranial aneurysms and arachnoid cysts were found in 34 and 25 patients, respectively, with no significant difference in frequency. Genotype, sex, estimated glomerular filtration rate and age at ADPKD diagnosis significantly affected the age at brain MRI. The proportional hazard risk analyzed using the age at brain MRI adjusted by these four variables was 5.0-times higher in the PKD1 group than in the PKD2 group for arachnoid cysts (P = 0.0357), but it was not different for intracranial aneurysms (P = 0.1605). Arachnoid cysts were diagnosed earlier in the PKD1 group than in the PKD2 group (54.8 vs 67.7 years, P = 0.0231), but no difference was found for intracranial aneurysms (P = 0.4738) by Kaplan-Meier analysis.

CONCLUSIONS

this study demonstrated the correlation between arachnoid cysts and PKD1 mutation. The reported association of arachnoid cysts with advanced renal disease may be due to the common correlation of these factors with PKD1 mutation.

Simultaneous brain and lung metastases of pancreatic ductal adenocarcinoma after curative pancreatectomy: a case report and literature review

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) rarely metastasizes to the brain; therefore, the features of brain metastasis of PDAC are still unknown. We encountered simultaneous metastases to the brain and lung in a PDAC patient after curative surgery. Case presentation A 68-year-old man with PDAC in the tail of the pancreas underwent distal pancreato-splenectomy. He received gemcitabine as adjuvant chemotherapy for 6 months. Two months later, brain and lung metastases occurred simultaneously. Considering the systemic condition, the patient received gamma knife treatment and an Ommaya reservoir was inserted for drainage. The patient's condition gradually worsened and he received the best supportive care. To the best of our knowledge, only 28 cases in which brain metastases of PDAC were identified at the time of ante-mortem have been reported to date, including the present case. Notably, the percentage of simultaneous brain and lung metastases was higher (32%) in a series of reviewed cohorts. Thus, lung metastasis might be one of the risk factors for the development of brain metastasis in patients with PDAC. As a systemic disease, it can be inferred that neoplastic cells will develop brain metastasis via hematogenous dissemination beyond the blood-brain barrier, even if local recurrence is controlled. In our case, immunohistochemical staining showed that the neoplastic cells were positive for carbonic anhydrase 9 (CAIX), mucin core protein 1 (MUC1), and MUC5AC in the resected primary PDAC.

CONCLUSION

We describe a case of simultaneous brain and lung metastases of PDAC after curative pancreatectomy, review previous literature, and discuss the clinical features of brain metastasis of PDAC.

[Microvascular decompression in trigeminal neuralgia following vertebrobasilar dolichoectasia]

OBJECTIVE

To analyze our own results with literature data and substantiate microvascular decompression in patients with trigeminal neuralgia (TN) following vertebrobasilar dolichoectasia (VBD).

MATERIAL AND METHODS

A total of 504 patients with TN underwent surgery in 1998-2018. Patients with TN following VBD were included into a retrospective study. There were 4 men and 10 women aged 66 years (range 51-80). Outcomes were evaluated using BNI (Barrow Neurological Institute) scale. PubMed database was used for literature review.

RESULTS

TN caused by VBD was diagnosed in 2.8% of patients. Left-sided trigeminal pain was observed in 10 patients, right-sided - in 4 cases. One patient had concomitant hemifacial spasm. MVD followed by shielding of trigeminal nerve root with shredded Teflon was performed in all patients. We did not perform fixation of vertebrobasilar vessels. In one case, open partial trigeminal nerve root rhizotomy was done in addition to MVD. All patients had pain-free early postoperative period. There were no deaths or major complications. There was transient cranial nerve dysfunction lasting no more than three months (facial numbness - 1, IV nerve dysfunction - 1, VI nerve dysfunction - 1, transient partial facial palsy (House-Brackmann II) - 2, hipoacusia - 2 patients). There was no facial pain recurrence in our group. Mean follow-up period was 5.5 years (range 6 months - 16 years).

CONCLUSION

MVD is an effective option in the treatment of TN following VBD. In these cases, operation is technically more difficult compared to MVD with intact vessels. However, surgery is much more effective than all the available alternatives. The possibilities of vessel transposition in VBD with or without fixation are limited and ineffective. Teflon wool interposition at the points of conflict is an effective and sufficient technique.

Role of TRPP2 in mouse airway smooth muscle tension and respiration

The transient receptor potential polycystin-2 (TRPP2) is encoded by the Pkd2 gene, and mutation of this gene can cause autosomal dominant polycystic kidney disease (ADPKD). Some patients with ADPKD experience extrarenal manifestations, including radiologic and clinical bronchiectasis. We hypothesized that TRPP2 may regulate airway smooth muscle (ASM) tension. Thus, we used smooth muscle-Pkd2 conditional knockout (Pkd2^SM-CKO) mice to investigate whether TRPP2 regulated ASM tension and whether TRPP2 deficiency contributed to bronchiectasis associated with ADPKD. Compared with wild-type mice, Pkd2^SM-CKO mice breathed more shallowly and faster, and their cross-sectional area ratio of bronchi to accompanying pulmonary arteries was higher, suggesting that TRPP2 may regulate ASM tension and contribute to the occurrence of bronchiectasis in ADPKD. In a bioassay examining isolated tracheal ring tension, no significant difference was found for high-potassium-induced depolarization of the ASM between the two groups, indicating that TRPP2 does not regulate depolarization-induced ASM contraction. By contrast, carbachol-induced contraction of the ASM derived from Pkd2^SM-CKO mice was significantly reduced compared with that in wild-type mice. In addition, relaxation of the carbachol-precontracted ASM by isoprenaline, a β-adrenergic receptor agonist that acts through the cAMP/adenylyl cyclase pathway, was also significantly attenuated in Pkd2^SM-CKO mice compared with that in wild-type mice. Thus, TRPP2 deficiency suppressed both contraction and relaxation of the ASM. These results provide a potential target for regulating ASM tension and for developing therapeutic alternatives for some ADPKD complications of the respiratory system or for independent respiratory disease, especially bronchiectasis.

Incremental health care resource utilization and expenditures associated with autosomal-dominant polycystic kidney disease

Purpose

Incremental health care resource utilization and expenditures associated with autosomal dominant polycystic kidney disease (ADPKD) were estimated.

Methods

Study data were from a large administrative claims database. Individuals aged 18 years or older enrolled in tracked health plans for 12 months from April 1, 2011 through March 31, 2012, and with an International Classification of Disease, Ninth Revision, Clinical Modification diagnosis code for "polycystic kidney, autosomal dominant" (753.13) or for "polycystic kidney, unspecified type" (753.12) were identified as having ADPKD, and linked one-to-one with individuals without ADPKD based on age and gender. Zero-inflated negative binomial models estimated incremental health care resource utilization and expenditures, adjusting for risk factors.

Results

A total of 3,844 individuals with ADPKD who satisfied selection criteria were linked one-to-one with 3,844 individuals without ADPKD. Multivariate, regression models adjusting for risk factors revealed incremental mean (standard error) resource use associated with ADPKD of 0.68 (0.090) hospital days, equal to 68 additional hospital days per 100 ADPKD patients, and 6.9 (0.28) outpatient visits, equal to 690 additional visits per 100 ADPKD patients. Mean (standard error) incremental total expenditures associated with ADPKD were US$8,639 ($470). Mean incremental expenditures were largest for outpatient expenditures at US$4,918 ($198), followed by mean incremental hospital expenditures of US$2,603 ($263), and mean incremental medication expenditures of US$1,589 ($77). Based on sub-group analysis, mean incremental total expenditures were US$2,944 ($417) among ADPKD patients without end-stage renal disease and US$38,962 ($6,181) for those with end-stage renal disease.

Conclusion

ADPKD was associated with considerable incremental health care resource utilization and expenditures. Significant illness burden was found even before patients reached end-stage renal disease.

Cerebral Aneurysm Associated with an Arachnoid Cyst: 3 Case Reports and a Systematic Review of the Literature

BACKGROUND

Arachnoid cysts and intracranial aneurysms are not rare, but it is unusual for an aneurysm to be associated with an arachnoid cyst. The objective of this study was to reveal the association between arachnoid cysts and intracranial aneurysms.

METHODS

Methods included to report 3 cases with these 2 pathologies and to perform a systematic review of the English and Japanese literature using PubMed, Scopus, and Ichushi Web.

RESULTS

The first case was of a 46-year-old man with a subarachnoid hemorrhage on the basal cistern and bilateral arachnoid cysts in the middle fossa, the second was that of a 29-year-old woman with a subarachnoid hemorrhage at the basal cistern and an arachnoid cyst in the left middle fossa, and the third was that of a 60-year-old man with a right putaminal hemorrhage and contralateral unruptured aneurysm and arachnoid cyst. A literature search for similar cases found 27 patients.

CONCLUSIONS

It was difficult to diagnose a ruptured aneurysm in some cases with an arachnoid cyst because computed tomography scan showed atypical findings, such as no hemorrhage, intracystic localized hemorrhage, or subdural hematoma. This review revealed that aneurysms and arachnoid cysts were significantly located ipsilaterally and that they occurred together in relatively young patients.

Frequency of Nerve Root Sleeve Cysts in Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

There is sporadic data about the occurrence of spinal meningeal cysts in patients with autosomal dominant polycystic kidney disease (ADPKD). We suggest that there is a relationship with the frequency and size of spinal meningeal cysts and headache, intracranial aneurysms, and cerebrospinal fluid leakage in patients with ADPKD.

AIM

To investigate the relationship with spinal meningeal cyst, cerebrospinal fluid leakage, and headache in patients with ADPKD.

STUDY DESIGN

Cross-sectional study.

METHODS

We enrolled 50 patients with ADPKD and 37 healthy volunteers. This cross-sectional study included patients with ADPKD and matched healthy volunteers. Magnetic resonance imaging myelography was performed using the 3D-T2 HASTE technique in an MRI scanner. We questioned our subjects regarding presence of headache and evaluated headache severity using a visual analog scale. The relationship between the number and size of spinal meningeal cysts with headache, intracranial aneurysms, and liver cysts was also investigated.

RESULTS

Spinal meningeal cysts were more numerous and larger in patients than in controls (14.8±11.6 vs. 6.4±4.6 cysts respectively, p<0.001, 68.3±49.3 vs. 25.4±20.1 mm, p<0.001, respectively). Spinal cyst number and size were similar in APDKD patients with or without intracranial aneurysms. Headache score was correlated with the size and number of spinal meningeal cysts. This was valid only in patients with ADPKD.

CONCLUSION

Abnormality involving the vessel wall in ADPKD may explain the increased number of spinal meningeal cysts in ADPKD. Moreover, leakage of cerebrospinal fluid secondary to spinal meningeal cyst may be responsible for recurrent severe headache by causing spontaneous intracranial hypotension in these patients.

Dialysis-induced Subdural Hematoma in an Arachnoid Cyst Associated with Autosomal Dominant Polycystic Kidney Disease

Arachnoid cyst (AC) is a neurological complication of autosomal dominant polycystic kidney disease (ADPKD). Although an AC can increase the risk of a subdural hematoma, the clinical presentation of bleeding into an AC associated with ADPKD is not well known. We herein report the case of a 59-year-old woman in whom the initiation of hemodialysis for renal failure led to AC bleeding. A change of anticoagulant from heparin to nafamostat mesilate allowed dialysis to continue without rebleeding. These findings suggest that hemodialysis in patients with an AC associated with ADPKD may increase the risk of bleeding. Nafamostat mesilate may be useful in such cases.

Growth of arachnoid cysts in patients with autosomal dominant polycystic kidney disease: serial imaging and clinical relevance

Background

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder that results in the growth of cysts in the kidneys and other organs. Multisystemic involvement is common including affection of the central nervous system with cerebral aneurysms and arachnoid cysts.

Methods

This is a prospective cohort study to investigate the prevalence and growth rate of arachnoid cysts in ADPKD patients. Participants enrolled in the SUISSE ADPKD cohort were offered cranial imaging for the detection of intracranial alterations. In the case of identified arachnoid cysts, patients were suggested to undergo follow-up imaging to assess the growth rate of the cysts. Volume of arachnoid cysts at the baseline and at follow-up visits was assessed by manual segmentation on a dedicated workstation.

Results

A total of 109 ADPKD patients agreed to undergo cranial imaging. In 14 (12.8%) patients (9 males and 5 females), 18 singular arachnoid cysts were identified. The baseline volumes of individual cysts ranged from 1.8 to 337.6 cm³. During a mean follow-up period of 24 months, the volume changes of 12 individual arachnoid cysts of nine patients ranged from −3.1 to 3.7 cm³. Cystic lesions were mostly localized in the middle fossa. All affected patients were clinically asymptomatic.

Conclusions

We found a higher prevalence of arachnoid cysts in ADPKD patients with more advanced disease. There was a large variability in size and growth. These arachnoid cysts were clinically silent and their growth pattern was subtle and unpredictable, in contrast to the much more foreseeable growth of the renal cysts.

Complete heart block with diastolic heart failure and pulmonary edema secondary to enlarging previously diagnosed thrombosed aneurysm of sinus of valsalva in a patient with history of autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is associated with vascular aneurysms that can affect any part of the vascular tree, like ascending aorta or coronary arteries. Sinus of Valsalva is known as an anatomical dilation at the root of aorta above the aortic valve and very few cases show aneurysm at that site in patients with ADPKD. Sinus of Valsalva aneurysm (SVA) can present with rupture and acute heart failure and infective endocarditis or could be asymptomatic accidentally discovered during cardiac catheterization. We report a case of a 76-year-old male with a unique constellation of cardiovascular anomalies associated with ADPKD. Patient was previously diagnosed with aneurysms affecting ascending aorta, sinus of Valsalva, and coronary arteries. Several years later, he came with complete heart block which was discovered later to be secondary to enlargement of his previously diagnosed thrombosed SVA. His case was complicated with acute heart failure and pulmonary edema. Conclusion. Patients with ADPKD can present with extrarenal manifestations. In our case, aneurysm at sinus of Valsalva was progressively enlarging and presented with complete heart block.

Arachnoid cysts in tuberous sclerosis complex

OBJECTIVE

Some clinical findings in tuberous sclerosis complex (TSC), such as hypomelanotic macules or angiofibromas are related to problems in development of the neural crest, which is also the origin of cranial leptomeninges. Arachnoid cysts have been reported in two TSC patients to date. The purpose of this study was to assess the prevalence and characteristics of arachnoid cysts in a large cohort of TSC.

MATERIALS AND METHOD

We performed a review of brain MRIs of 220 TSC patients searching for arachnoid cysts.

RESULTS

Arachnoid cysts were found in 12 (5.5%) (general population: 0.5%), including ten males (83.3%). Four patients (33.3%) had also autosomal dominant polycystic kidney disease (ADPKD) due to a contiguous deletion of the TSC2-PKD1 genes. Three patients (25%) had two or more arachnoid cysts, of whom two also had ADPKD. One patient with an arachnoid cyst did not have tubers, subependymal nodules or white matter migration lines.

CONCLUSION

Our study suggests that arachnoid cysts are part of the clinical spectrum of TSC and may be also present in TSC patients without other typical TSC brain lesions.

Translational research in ADPKD: lessons from animal models

Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in PKD1 or PKD2, which encode polycystin-1 and polycystin-2, respectively. Rodent models are available to study the pathogenesis of polycystic kidney disease (PKD) and for preclinical testing of potential therapies-either genetically engineered models carrying mutations in Pkd1 or Pkd2 or models of renal cystic disease that do not have mutations in these genes. The models are characterized by age at onset of disease, rate of disease progression, the affected nephron segment, the number of affected nephrons, synchronized or unsynchronized cyst formation and the extent of fibrosis and inflammation. Mouse models have provided valuable mechanistic insights into the pathogenesis of PKD; for example, mutated Pkd1 or Pkd2 cause renal cysts but additional factors are also required, and the rate of cyst formation is increased in the presence of renal injury. Animal studies have also revealed complex genetic and functional interactions among various genes and proteins associated with PKD. Here, we provide an update on the preclinical models commonly used to study the molecular pathogenesis of ADPKD and test potential therapeutic strategies. Progress made in understanding the pathophysiology of human ADPKD through these animal models is also discussed.

Bilateral cysts in the choroid plexus in a patient with autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic systemic disorder, which is associated with cyst formation in several organs, renal function decline and a higher prevalence of intracranial aneurysms. We report a 52-year-old, otherwise healthy, man with ADPKD who had asymptomatic, bilateral, multiple cysts in the choroid plexus, which is an extremely rare abnormality. Recent evidence suggests that the polycystin proteins, which are dysfunctional in ADPKD, are found in ciliated choroid plexus cells that are involved with regulation of cerebrospinal fluid homeostasis. We hypothesize therefore that choroid plexus cysts may be part of the ADPKD phenotype, which has not been described before.

The TRPP subfamily and polycystin-1 proteins

It has been exciting times since the identification of polycystic kidney disease 1 (PKD1) and PKD2 as the genes mutated in autosomal dominant polycystic kidney disease (ADPKD). Biological roles of the encoded proteins polycystin-1 and TRPP2 have been deduced from phenotypes in ADPKD patients, but recent insights from vertebrate and invertebrate model organisms have significantly expanded our understanding of the physiological functions of these proteins. The identification of additional TRPP (TRPP3 and TRPP5) and polycystin-1-like proteins (PKD1L1, PKD1L2, PKD1L3, and PKDREJ) has added yet another layer of complexity to these fascinating cellular signalling units. TRPP proteins assemble with polycystin-1 family members to form receptor-channel complexes. These protein modules have important biological roles ranging from tubular morphogenesis to determination of left-right asymmetry. The founding members of the polycystin family, TRPP2 and polycystin-1, are a prime example of how studying human disease genes can provide insights into fundamental biological mechanisms using a so-called "reverse translational" approach (from bedside to bench). Here, we discuss the current literature on TRPP ion channels and polycystin-1 family proteins including expression, structure, physical interactions, physiology, and lessons from animal model systems and human disease.

Extra-renal manifestations of autosomal dominant polycystic kidney disease (ADPKD): considerations for routine screening and management

Autosomal-dominant polycystic kidney disease (ADPKD) is a systemic disease, marked by progressive increase of bilateral renal cysts, resulting in chronic kidney disease (CKD) and often leading to end-stage renal disease (ESRD). Apart from renal cysts, patients often have extra-renal disease, involving the liver, heart and vasculature. Other less common but equally important extra-renal manifestations of ADPKD include diverticular disease, hernias, male infertility and pain. Extra-renal disease burden is often asymptomatic, but may result in increased morbidity and mortality. If the disease burden is significant, screening may prove beneficial. We review the rationale for current screening recommendations and propose some guidelines for screening and management of ADPKD patients.

Intracranial aneurysms in autosomal dominant polycystic kidney disease

BACKGROUND AND PURPOSE

ADPKD correlates with an increased frequency of ICANs, but universal screening for ICANs in patients with ADPKD is not currently recommended. The aim of our study was to determine which groups might benefit from screening by determining the prevalence of ICANs in the Polish ADPKD population and identifying any subgroups with an increased risk for ICANs.

MATERIALS AND METHODS

Eighty-three adult, predialysis-phase patients with ADPKD underwent screening for ICANs with MRA of the brain.

RESULTS

The prevalence of ICANs in the studied population was 16.9%, with 6% of the screened group requiring neurosurgical intervention. We also found that the frequency of ICANs increases with age, reaching 22.4% in patients older than 45 years. All diagnosed ICANs were small (< 9 mm) and were localized in the anterior circulation. In addition, MR imaging revealed arachnoid cysts in 4.8% of patients with ADPKD.

CONCLUSIONS

We suggest that patients older than 45 years with ADPKD be considered as candidates for screening for ICANs, and we propose a clinical algorithm for this subgroup. However, we could not find risk factors for ICANs in younger patients with ADPKD.

Systematic review of structural and functional neuroimaging findings in children and adults with CKD

CKD has been linked with cognitive deficits and affective disorders in multiple studies. Analysis of structural and functional neuroimaging in adults and children with kidney disease may provide additional important insights into the pathobiology of this relationship. This paper comprehensively reviews neuroimaging studies in both children and adults. Major databases (PsychLit, MEDLINE, WorldCat, ArticleFirst, PubMed, Ovid MEDLINE) were searched using consistent search terms, and studies published between 1975 and 2012 were included if their samples focused on CKD as the primary disease process. Exclusion criteria included case reports, chapters, and review articles. This systematic process yielded 43 studies for inclusion (30 in adults, 13 in children). Findings from this review identified several clear trends: (1) presence of cerebral atrophy and cerebral density changes in patients with CKD; (2) cerebral vascular disease, including deep white matter hyperintensities, white matter lesions, cerebral microbleeds, silent cerebral infarction, and cortical infarction, in patients with CKD; and (3) similarities in regional cerebral blood flow between patients with CKD and those with affective disorders. These findings document the importance of neuroimaging procedures in understanding the effect of CKD on brain structure, function, and associated behaviors. Results provide a developmental linkage between childhood and adulthood, with respect to the effect of CKD on brain functioning across the lifespan, with strong implications for a cerebrovascular mechanism contributing to this developmental linkage. Use of neuroimaging methods to corroborate manifest neuropsychological deficits or perhaps to indicate preventive actions may prove useful to individuals with CKD.

Prevalence and natural history of arachnoid cysts in adults

Object

Arachnoid cysts are a frequent finding on intracranial imaging. The prevalence and natural history of these cysts in adults are not well defined.

Methods

We retrospectively reviewed the electronic medical records of a consecutive series of adults who underwent brain MRI over a 12-year interval to identify those with arachnoid cysts. The MRI studies were reviewed to confirm the diagnosis. For those patients with arachnoid cysts, we evaluated presenting symptoms, cyst size, and cyst location. Patients with more than 6 months' clinical and imaging follow-up were included in a natural history analysis.

Results

A total of 48,417 patients underwent brain MRI over the study period. Arachnoid cysts were identified in 661 patients (1.4%). Men had a higher prevalence than women (p < 0.0001). Multiple arachnoid cysts occurred in 30 patients. The most common locations were middle fossa (34%), retrocerebellar (33%), and convexity (14%). Middle fossa cysts were predominantly left-sided (70%, p < 0.001). Thirty-five patients were considered symptomatic and 24 underwent surgical treatment. Sellar and suprasellar cysts were more likely to be considered symptomatic (p < 0.0001). Middle fossa cysts were less likely to be considered symptomatic (p = 0.01. The criteria for natural history analysis were met in 203 patients with a total of 213 cysts. After a mean follow-up of 3.8 ± 2.8 years (for this subgroup), 5 cysts (2.3%) increased in size and 2 cysts decreased in size (0.9%). Only 2 patients developed new or worsening symptoms over the follow-up period.

Conclusions

Arachnoid cysts are a common incidental finding on intracranial imaging in all age groups. Although arachnoid cysts are symptomatic in a small number of patients, they are associated with a benign natural history for those presenting without symptoms.

Meningeal tumor: A rare extrahepatic association in patients with polycystic liver disease enrolled for liver transplantation

In the present study, we described a rare association of polycystic liver disease (PCLD) with intracranial meningiomas in patients included on a liver transplant list, focusing on the diagnosis, treatment and possible association with any genetic alterations. Two female patients, aged 39 and 49 years were included on a liver transplant list due to extensive PCLD, with symptoms related to an abdominal compartmental syndrome. Screening for extrahepatic manifestation revealed a right frontal meningioma in the first patient, and a parietal posterior calcified meningioma in the second patient, measuring 1 and 7×3×2 cm in diameter, respectively. Following tumor removal, the histological pattern was compatible with fibrous and transitional meningioma, respectively. Cytogenetic studies conducted following surgery did not reveal any changes in metaphase chromosomes. The postoperative follow-up for the two patients was uneventful, without complications, with the patients remaining on a liver transplant waiting list. We conclude that screening for extrahepatic manifestations of PCLD is mandatory, as certain lesions require treatment prior to liver transplantation. The lack of a genetic or familial association between these two cases show they are likely to have occurred by chance, rather than representing a previously unrecognized association between polycystic liver disease and cranial meningioma.

TRPP channels and polycystins

The founding member of the TRPP family, TRPP2, was identified as one of the disease genes causing autosomal dominant polycystic kidney disease (ADPKD). ADPKD is the most prevalent, potentially lethal, monogenic disorder in humans, with an average incidence of one in 400 to one in 1,000 individuals worldwide. Here we give an overview of TRPP ion channels and Polycystin-1 receptor proteins focusing on more recent studies. We include the Polycystin-1 family since these proteins are functionally linked to TRPP channels.

Congenital fibrocystic liver diseases

Fibrocystic diseases affecting the liver and often also other organs like the kidneys are a clinically and genetically heterogeneous group of disorders that may present in utero or remain clinically silent into late adulthood. During recent years, substantial progress has been made in unravelling the aetiology with primary cilia playing a central pathogenic role in many if not all of these diseases. The fibrocystogenic process shares some common features including proliferation and dilatation of epithelial bile ducts with concomitant abnormal apoptosis, fluid secretion and extracellular matrix deposition. In this review, we summarise clinical and diagnostic aspects, mechanisms of hepatic cystogenesis, and recent knowledge on potential therapies for these conditions.

Extrarenal manifestations of autosomal dominant polycystic kidney disease

Although asymptomatic in most patients, extrarenal manifestations of ADPKD may become more clinically relevant with the increasing life expectancy of affected patients. They mainly encompass cysts in other organs than the kidney (liver: 94%, seminal vesicle: 40%, pancreas: 9%, arachnoid membrane: 8%, and spinal meningeal, 2%) and connective tissue abnormalities (mitral valve prolapse: 25%, intracranial aneurysms: 8%, and abdominal hernia: 10%). Their recognition may spare the patient from other, useless investigations (eg, when an arachnoid cyst is incidentally found) or lead to the implementation of prophylactic or therapeutic measures (eg, screening, sometimes followed by the treatment of an asymptomatic intracranial aneurysm in at-risk patients, or, in the presence of a severe polycystic liver disease, avoidance from estrogens and treatment aimed to slow cyst growth).

Sacral radicular cysts in autosomal dominant polycystic kidney disease

This is the first report of a case of sacral radicular cysts in a patient with autosomal dominant polycystic kidney disease (ADPKD). A 46-year-old woman with ADPKD was found to have bilateral sacral radicular cysts discovered incidentally by magnetic resonance imaging (MRI). Cysts arising from arachnoid or spinal meningeal sac should be considered one of the manifestations of a more widespread connective tissue disorder associated with ADPKD.

Intracranial aneurysm and arachnoid cyst: a rare association between two cerebral malformations

Intracranial aneurysms and arachnoid cysts are cerebral disorders of a high prevalence. However, association between both malformations is a rare finding. The aim was to analyse this association with regard to the different clinical presentations according to the haemorrhage types, as well as the pathogenesis of this association. We searched the English language literature in MEDLINE database in order to include all manuscripts in which this association was found. A new case of a 55-year-old man with a large posterior communicating artery aneurysm and a middle cranial fossa arachnoid cyst presenting with headache and seizure was added to review of the literature and presented as an illustrative case. Nine cases were found. Six were male and three were female. The mean age was 42 years (range 29-66 years). All but one arachnoid cysts were located at middle cranial fossa, aneurysms arose from middle cerebral artery in three cases, internal carotid artery bifurcation in two cases, posterior communicating segment of carotid artery in two cases, anterior communicating artery in one case and azygos pericallosal artery in one case. Clinical presentation was related to aneurysmal rupture in six cases (subarachnoid haemorrhage in four, subdural haematoma in one and intracystic haematoma in two) and related to arachnoid cysts in three cases, where the most common symptoms were seizures and headache. Association between intracranial aneurysms and arachnoid cysts is a rare finding that can present with signs and symptoms related to aneurysm rupture, or with mass effect and seizures related to the cyst. The aneurysmal haemorrhage may be atypical, since it can be into the subarachnoid space, into the arachnoid cyst, or into the subdural space.

Rhombencephalosynapsis associated with autosomal dominant polycystic kidney disease Type 1

Rhombencephalosynapsis (RES) is a rare congenital malformation of the cerebellum characterized by hypogenesis or agenesis of the vermis and fusion of the cerebellar hemispheres with or without fusion of the dentate nuclei and superior cerebellar peduncles. No genetic or chromosomal abnormalities have been identified for RES. Although the occurrence of RES is presumed to be sporadic, no clear pattern of inheritance has been identified. The authors report on a 17-year-old girl with autosomal dominant polycystic kidney disease Type 1 as well as RES.

A FORM OF DYSPLASIA OR A FORTUITOUS ASSOCIATION? A CEREBRAL ANEURYSM INSIDE AN ARACHNOID CYST

OBJECTIVE

Although arachnoid cysts and intracranial aneurysms are very common lesions, their association in the same patient is rare. We present a case of a middle cerebral artery aneurysm ruptured into an arachnoid cyst. We found only six cases with intracystic hemorrhage reported in the literature. The presence of an arachnoid cyst can mislead clinical presentation. The patient presented a paradoxically small temporal fossa and thickening of the temporal and sphenoid bone. The authors suggest that this uncommon association (arachnoid cyst, atypical cranial vault, and “mirror-like” cerebral aneurysm) could represent a form of dysplasia.

CLINICAL PRESENTATION

A 46-year-old patient presented with a 3-week history of slight headaches, which had worsened in the last 3 days before presentation. Computed tomographic scans showed a cystic lesion located in the middle cranial fossa and sylvian fissure with suspected aneurysm dilation inside. Magnetic resonance imaging scans showed an intracystic hemorrhage but not subarachnoid hemorrhage. Paradoxically, changes in the cranial vault around the cyst were noted. Digital subtraction angiography showed bilateral “mirror” middle cerebral artery aneurysms.

INTERVENTION

A large right pterional craniotomy was performed with full microsurgical removal of the arachnoid cyst walls and aneurysm clipping. The aneurysm was in the medial wall of the arachnoid cyst with its dome inside the cyst. The contralateral aneurysm was clipped 2 weeks later. The follow-up period was uneventful, and the patient returned to normal life.

CONCLUSION

Rupture of a cerebral aneurysm into an arachnoid cyst is rare. Clinical presentation may be unusual because the cyst can prevent subarachnoid hemorrhage. A middle fossa cranial arachnoid cyst in the presence of temporal bone depression, small middle fossa, and thickness of squamous temporal bone and the lesser wing of sphenoid is rare and suggests that congenital factors may play an important role in their development. The exceptional association between “mirror” aneurysms and arachnoid cyst with bone changes suggests a possible congenital form of dysplasia.

Autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease is the most prevalent, potentially lethal, monogenic disorder. It is associated with large interfamilial and intrafamilial variability, which can be explained to a large extent by its genetic heterogeneity and modifier genes. An increased understanding of the disorder's underlying genetic, molecular, and cellular mechanisms and a better appreciation of its progression and systemic manifestations have laid out the foundation for the development of clinical trials and potentially effective treatments.

Renal and extrarenal manifestations of autosomal dominant polycystic kidney disease

The objective of the present study was to determine the frequency of the most common clinical features in patients with autosomal dominant polycystic kidney disease in a sample of the Brazilian population. The medical records of 92 patients with autosomal dominant polycystic kidney disease attended during the period from 1985 to 2003 were reviewed. The following data were recorded: age at diagnosis, gender, associated clinical manifestations, occurrence of stroke, age at loss of renal function (beginning of dialysis), and presence of a family history. The involvement of abdominal viscera was investigated by ultrasonography. Intracranial alterations were prospectively investigated by magnetic resonance angiography in 42 asymptomatic patients, and complemented with digital subtraction arteriography when indicated. Mean age at diagnosis was 35.1 +/- 14.9 years, and mean serum creatinine at referral was 2.4 +/- 2.8 mg/dL. The most frequent clinical manifestations during the disease were arterial hypertension (63.3%), lumbar pain (55.4%), an abdominal mass (47.8%), and urinary infection (35.8%). Loss of renal function occurred in 27 patients (mean age: 45.4 +/- 9.5 years). The liver was the second organ most frequently affected (39.1%). Stroke occurred in 7.6% of the patients. Asymptomatic intracranial aneurysm was detected in 3 patients and arachnoid cysts in 3 other patients. In conclusion, the most common clinical features were lumbar pain, arterial hypertension, abdominal mass, and urinary infection, and the most serious complications were chronic renal failure and stroke. Both intracranial aneurysms and arachnoid cysts occurred in asymptomatic patients at a frequency of 7.14%.

New advances in evaluation and management of patients with polycystic liver disease

Adult polycystic liver disease (APLD) is an autosomal dominant condition most commonly associated with polycystic kidney disease. However, over the last decade it has come to be recognized that APLD is a genetically heterogeneous disorder involving derangements on at least three different chromosomes. Mutations involving chromosomes 16 and 4 accounting for autosomal dominant polycystic kidney disease (ADPKD) type 1 and type 2 have been well described as have their gene products, polycystin-1 and polycystin-2. These have since been joined by a more recently recognized mutation in the short arm of chromosome 19 thought to be responsible for a much rarer form of autosomal dominant polycystic liver disease without any associated renal involvement. Despite the sometimes impressive physical and radiologic findings, only a minority of patients will progress to advanced liver disease or develop complications as a result of massive hepatomegaly. In these patients, medical management alone has proved ineffectual. Therefore, in the symptomatic APLD patient, surgical therapy remains the mainstay of therapy and includes cyst aspiration and sclerosis, fenestration with and without hepatic resection and orthotopic liver transplantation. The surgical literature on treatment of APLD, to include outcome measurements and complication rates are summarized. Additionally, we review other potential organ involvement and resultant complications.

Chronic subdural haematoma and arachnoid cyst in autosomal dominant polycystic kidney disease (ADPKD)

We present the unusual association between chronic subdural haematoma (CSDH), intracranial arachnoid cyst and autosomal dominant polycystic kidney disease (ADPKD) in a 27-year-old man. CSDH is a documented complication of intracranial arachnoid cyst, the incidence of which is increased in patients with ADPKD. Awareness of this association may lead to earlier diagnosis of ADPKD and treatment of its systemic complications, including renal insufficiency, systemic hypertension and previously unsuspected intracranial saccular aneurysm. Surgery for CSDH associated with intracranial arachnoid cyst may be complicated by over-drainage of cerebrospinal fluid due to communication between the cyst and the cisternal subarachnoid space, as illustrated in the present case, and the development of epidural haemorrhage.

Case Report. Chronic subdural haematoma and autosomal polycystic kidney disease: Report of two new cases

Chronic subdural haematoma (SDH) was recently described in some patients who were suffering from autosomic dominant polycystic kidney disease (ADPKD). It results in various neurological symptoms mimicking those related to intracranial aneurysms, which are relatively frequent in such patients. The authors report two cases of chronic SDH observed in two patients known to have advanced renal failure attributed to ADPKD. Medical imaging failed to reveal features of associated intracranial abnormalities such as aneurysms or arachnoid cysts. Surgical drainage resulted in a good recovery without relapse during a long period of follow up that exceeded 10 years in the first case.

Retrocerebellar arachnoid cysts in siblings with mental retardation and undescended testis

Arachnoid cysts comprise approximately 1% of all intracranial space-occupying lesions and usually occur sporadically. We report retrocerebellar arachnoid cysts in two male siblings with mental retardation and undescended testis, suggesting the possibility of a genetic basis for at least some cases of retrocerebellar arachnoid cysts.

Familial arachnoid cysts in association with autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a systemic disorder well-known for its association with intracranial aneurysms. Recently, intracranial arachnoid cysts have also been reported to be associated with ADPKD. We describe a father and daughter who each has a posterior fossa arachnoid cyst and asymptomatic ADPKD. To our knowledge, this is the first report of familial occurrence of arachnoid cysts in association with ADPKD.

Pain management in polycystic kidney disease

Pain is a common complaint in patients with autosomal-dominant polycystic kidney disease, and a systematic approach is needed to differentiate the etiology of the pain and define an approach to management. A thorough history is the best clue to the multifactorial causes of the pain, superimposed upon an understanding of the complex innervation network that supplies the kidneys. The appropriate use of diagnostic radiology (especially MRI) will assist in differentiating the mechanical low back pain caused by cyst enlargement, cyst rupture and cyst infection. Also, the increased incidence of uric acid nephrolithiasis as a factor in producing renal colic must be considered when evaluating acute pain in the population at risk. MRI is not a good technique to detect renal calculi, a frequent cause of pain in polycystic kidney disease. If stone disease is a possibility, then abdominal CT scan and/or ultrasound should be the method of radiologic investigation. Pain management is generally not approached in a systematic way in clinical practice because most physicians lack training in the principles of pain management. The first impulse to give narcotics for pain relief must be avoided. Since chronic pain cannot be "cured," an approach must include techniques that allow the patient to adapt to chronic pain so as to limit interference with their life style. A detailed stepwise approach for acute and chronic pain strategies for the patient with autosomal dominant polycystic kidney disease is outlined.

Molecular genetics of pineal region neoplasms

A large variety of mass lesions have been reported in the region of the pineal gland. Pineal parenchymal tumors and germ cell tumors (GCTs) are especially characteristic of this region. Despite their rarity, a number of excellent studies on the cytogenetics and molecular genetics of pineal parenchymal tumors and pineal region GCTs have been published. These studies draw attention to a number of distinct genomic regions recurrently involved in the various subtypes of malignancies of the pineal gland. Outcomes for tumors in this location vary widely between patients and among differing histologies. Development of novel therapies for patients with poor prognoses will depend on the acquisition of a more detailed understanding of the molecular basis associated with the etiopathogenesis of these neoplasms. We review the literature on cytogenetics, familial syndromes, animal models and molecular genetics of pineal region neoplasms.

[Cerebral aneurysm and arachnoid cyst: about a case with intracystic hemorrhage]

We report a case of a carotid artery bifurcation aneurysm which ruptured into a silvian fissure arachnoid cyst. In the review of the literature, only three cases were before reported. We discuss about uncommon clinical findings, the surgical aspects and the associations among the lesions.

Chronic subdural hematoma in autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) has been associated with an increased incidence of aneurysmal subarachnoid hemorrhage and intracerebral hematomas. We describe five patients with chronic subdural hematomas, a previously unrecognized complication of ADPKD. In four of the five cases, no trigger was apparent. Clinical presentation was subtle, with mild hemiparesis, headache, or both in four patients and transient neurological deficits mimicking transient ischemic attacks in one patient. In three of the five patients, a retrocerebellar arachnoid cyst was found, suggesting a plausible causal relation between the intracranial arachnoid cysts and the subdural hematomas. In one patient, subdural hematoma was in close proximity to the frontally located arachnoid cyst.

Genetics of intracranial aneurysms

The etiology and pathogenesis of intracranial aneurysms are clearly multifactorial, with genetic factors playing an increasingly recognized role. Intracranial aneurysms have been associated with numerous heritable connective tissue disorders, which account for at least 5% of cases. Of these disorders, the most important are Ehlers-Danlos syndrome Type IV, Marfan's syndrome, neurofibromatosis Type 1, and autosomal dominant polycystic kidney disease; the association with intracranial aneurysms, however, has been firmly established only for polycystic kidney disease. Familial intracranial aneurysms are not rare but account for 7 to 20% of patients with aneurysmal subarachnoid hemorrhage and are generally not associated with any of the known heritable connective tissue disorders. First-degree relatives of patients with aneurysmal subarachnoid hemorrhage are at an approximately fourfold increased risk of suffering ruptured intracranial aneurysms, compared to the general population. Various possible modes of inheritance have been identified in families with intracranial aneurysms, suggesting genetic heterogeneity. Although the benefits have never been quantified, screening for asymptomatic intracranial aneurysms should be considered in families with two or more affected members. The yield of such a screening program may approximate 10%. Although it is unlikely that there is a single gene with major effect, much effort is currently being directed at locating intracranial aneurysm genes.