Browse

You are looking at 1 - 10 of 98 items for

  • Refine by Access: all x
  • By Author: Smyth, Matthew D. x
Clear All
Free access

Laser interstitial thermal therapy compared with open resection for treating subependymal giant cell astrocytoma

Diane J. Aum, Rebecca A. Reynolds, Sean D. McEvoy, Michael Wong, Jarod L. Roland, and Matthew D. Smyth

OBJECTIVE

Subependymal giant cell astrocytomas (SEGAs) are WHO grade 1 tumors associated with tuberous sclerosis that classically arise from the ventricular wall near the caudate groove and foramen of Monro. Laser interstitial thermal therapy (LITT) is a minimally invasive surgical technique, which works by heating a stereotactically placed laser fiber to ablative temperatures under MRI thermometry monitoring. In this paper, the authors present LITT as a surgical alternative to open resection of SEGAs.

METHODS

Twelve patients with SEGAs who underwent 16 procedures between 2007 and 2022 at a single institution were retrospectively reviewed. These patients underwent either open resection or LITT. Clinical data, imaging, recurrence rate, further treatments, and related complications were analyzed.

RESULTS

Among the 16 procedures, 9 were open resection and 7 were LITT. An external ventricular drain was placed in 66% (6/9) of open procedures and 57.1% (4/7) of LITT cases. A septostomy was performed in 56% (5/9) of open procedures and 29% (2/7) of LITT cases. Complication rates were higher in open cases than in LITT procedures (44% vs 0%, p < 0.05). Complications included hydrocephalus, transient venous ischemia, wound infection, and bone flap migration. The median length of hospital stay was 4 days (IQR 3.3–5.5 days) for open cases and 4 days (IQR 3.0–7.0 days) for LITT procedures. Recurrence or progression occurred after 3 open cases and 2 LITT cases (33% vs 33%, p = 0.803). For the recurrences, 2 open cases underwent stereotactic radiosurgery, 1 open case underwent LITT, and 1 LITT case underwent repeat LITT. Among the LITT cases, only the patients with no decrease in tumor size by 6 months experienced tumor progression afterward. The 2 LITT cases with progression were the only ones with calcification present on preoperative imaging. The median follow-up times for cases assessed for progression were 8.4 years (IQR 3.8–14.4 years) for open resection and 3.9 years (IQR 3.4–5.1 years) for LITT.

CONCLUSIONS

The small size of this case series limits generalizability or adequate comparison of safety. However, this series adds to the literature supporting LITT as a less invasive surgical alternative to open resection of SEGAs and demonstrates that LITT has similar recurrence and/or progression rates to open resection. Additional studies with more data are necessary for comprehensive comparisons between open resection and LITT for treating SEGA.

Restricted access

School-age anthropometric and patient-reported outcomes after open or endoscopic repair of sagittal craniosynostosis

Annahita R. Fotouhi, Kamlesh B. Patel, Gary B. Skolnick, Corinne M. Merrill, Katherine M. Hofmann, Esperanza Mantilla-Rivas, Brent R. Collett, Virginia D. Allhusen, Sybill D. Naidoo, Gary F. Rogers, Robert F. Keating, Matthew D. Smyth, and Suresh N. Magge

OBJECTIVE

Several studies have compared perioperative parameters and early postoperative morphology between endoscope-assisted strip craniectomy with orthotic therapy (endoscopic repair) and cranial vault remodeling (open repair). To extend these results, the authors evaluated school-age anthropometric outcomes after these techniques across three institutions.

METHODS

School-aged children (age range 4–18 years) with previously corrected isolated sagittal craniosynostosis were enrolled. Upon inclusion, 3D photographs and patient-reported outcomes were obtained, and the cephalic index and head circumference z-scores were calculated. Analyses of covariance models controlling for baseline differences and a priori covariates were performed.

RESULTS

Eighty-one participants (median [range] age 7 [4–15] years) were included. The mean (95% CI) school-age cephalic index was significantly higher in the endoscopic cohort, though within the normal range for both groups (endoscopic 78% [77%–79%] vs open 76% [74%–77%], p = 0.027). The mean change in the cephalic index from preoperation to school age was significantly greater in the endoscopic group (9% [7%–11%] vs open 3% [1%–5%], p < 0.001). Compared to preoperative measurements, mean school-age head circumference z-scores decreased significantly more in the open cohort (−1.6 [−2.2 to −1.0] vs endoscopic −0.3 [−0.8 to −0.2], p = 0.002). Patient-reported levels of stigma were within the normal limits for both groups.

CONCLUSIONS

Endoscopic and open repair techniques effectively normalize school-age anthropometric outcomes. However, endoscopic repair produces a clinically meaningful and significantly greater improvement in the school-age cephalic index, with maintenance of head growth. These findings demonstrate the importance of early referral by pediatricians and inform treatment decisions.

Restricted access

Multicenter comparison of head shape outcomes for three minimally invasive strip craniectomy techniques for sagittal craniosynostosis

Imran Rizvi, Rami R. Hallac, Emily L. Geisler, Jeyna K. Perez, Bar Y. Ainuz, Mark P. Pressler, Sarah A. Jackson, Gary B. Skolnick, Matthew D. Smyth, James R. Seaward, Christopher A. Derderian, Lisa R. David, Christopher M. Runyan, Kamlesh B. Patel, and Alex A. Kane

OBJECTIVE

A literature gap exists comparing whole head shape outcome following correction of sagittal craniosynostosis. The objective of this multicenter study was to provide an analysis of long-term results following three different endoscopic strip craniectomy techniques for correction of sagittal craniosynostosis: 1) spring-assisted strip craniectomy, 2) wide-strip craniectomy with biparietal and bitemporal barrel-stave wedge osteotomies plus helmet orthosis, and 3) narrow-strip craniectomy plus orthosis without barrel staves.

METHODS

Pre- and postoperative 3D stereophotogrammetric images were collected from patients who underwent craniosynostosis surgery. Procedures were divided among institutions as follows: spring-assisted strip craniectomies were performed at Atrium Health Wake Forest Baptist Hospital; narrow-strip craniectomies were performed at St. Louis Children’s Hospital by one craniofacial surgeon; and wide-vertex craniectomies were performed at St. Louis Children’s Hospital prior to 2010, and then continued at Children’s Medical Center Dallas. Pre- and postoperative 3D whole-head composite images were generated for each procedure to visually represent outcomes at final follow-up and compared with age-matched normal controls.

RESULTS

Patients in the spring-assisted strip craniectomy group showed normalization of frontal bossing and skull height compared with age-matched controls, whereas patients undergoing wide-strip craniectomy showed greater correction of occipital protrusion. Patients in the narrow-strip craniectomy cohort had intermediate results between these outcomes. Nested aggregate head shapes showed good correction of head shapes from all techniques.

CONCLUSIONS

This large, retrospective, multicenter study illustrated whole head shape outcomes from three different craniectomy procedures. Although each procedure showed some differences in loci of primary correction, all three surgical methods demonstrated good correction of primary scaphocephalic deformity.

Restricted access

Subependymal giant-cell astrocytomas in the absence of tuberous sclerosis

Rebecca A. Reynolds, Diane J. Aum, Ignacio Gonzalez-Gomez, Michael Wong, Kaleigh Roberts, Sonika Dahiya, Luis F. Rodriguez, Jarod L. Roland, and Matthew D. Smyth

OBJECTIVE

Tuberous sclerosis is a rare genetic condition caused by TSC1 or TSC2 mutations that can be inherited, sporadic, or the result of somatic mosaicism. Subependymal giant-cell astrocytoma (SEGA) is a major diagnostic feature of tuberous sclerosis complex (TSC). This study aimed to present a series of cases in which a pathological diagnosis of SEGA was not diagnostic of tuberous sclerosis.

METHODS

The authors retrospectively reviewed a clinical case series of 5 children who presented with a SEGA tumor to Johns Hopkins All Children’s Hospital and St. Louis Children’s Hospital between 2010 and 2022 and whose initial genetic workup was negative for tuberous sclerosis. All patients were treated with craniotomy for SEGA resection. TSC genetic testing was performed on all SEGA specimens.

RESULTS

The children underwent open frontal craniotomy for SEGA resection from the ages of 10 months to 14 years. All cases demonstrated the classic imaging features of SEGA. Four were centered at the foramen of Monro and 1 in the occipital horn. One patient presented with hydrocephalus, 1 with headaches, 1 with hand weakness, 1 with seizures, and 1 with tumor hemorrhage. Somatic TSC1 mutation was present in the SEGA tumors of 2 patients and TSC2 mutation in 1 patient. Germline TSC mutation testing was negative for all 5 cases. No patient had other systemic findings of tuberous sclerosis on ophthalmological, dermatological, neurological, renal, or cardiopulmonary assessments and thus did not meet the clinical criteria for tuberous sclerosis. The average follow-up was 6.7 years. Recurrence was noted in 2 cases, in which 1 patient underwent radiosurgery and 1 was started on a mammalian target of rapamycin (mTOR) inhibitor (rapamycin).

CONCLUSIONS

There may be intracranial implications of somatic mosaicism associated with tuberous sclerosis. Children who are diagnosed with SEGA do not necessarily have a diagnosis of tuberous sclerosis. Tumors may carry a TSC1 or TSC2 mutation, but germline testing can be negative. These children should continue to be followed with serial cranial imaging for tumor progression, but they may not require the same long-term monitoring as patients who are diagnosed with germline TSC1 or TSC2 mutations.

Free access

Magnetic resonance imaging–guided stereotactic laser ablation therapy for the treatment of pediatric epilepsy: a retrospective multiinstitutional study

Elsa V. Arocho-Quinones, Sean M. Lew, Michael H. Handler, Zulma Tovar-Spinoza, Matthew D. Smyth, Robert J. Bollo, David Donahue, M. Scott Perry, Michael Levy, David Gonda, Francesco T. Mangano, Benjamin C. Kennedy, Phillip B. Storm, Angela V. Price, Daniel E. Couture, Chima Oluigbo, Ann-Christine Duhaime, Gene H. Barnett, Carrie R. Muh, Michael D. Sather, Aria Fallah, Anthony C. Wang, Sanjiv Bhatia, Daniel Eastwood, Sergey Tarima, Sarah Graber, Sean Huckins, Daniel Hafez, Kavelin Rumalla, Laurie Bailey, Sabrina Shandley, Ashton Roach, Erin Alexander, Wendy Jenkins, Deki Tsering, George Price, Antonio Meola, Wendi Evanoff, Eric M. Thompson, Nicholas Brandmeir, and for the Pediatric Stereotactic Laser Ablation Workgroup

OBJECTIVE

The authors of this study evaluated the safety and efficacy of stereotactic laser ablation (SLA) for the treatment of drug-resistant epilepsy (DRE) in children.

METHODS

Seventeen North American centers were enrolled in the study. Data for pediatric patients with DRE who had been treated with SLA between 2008 and 2018 were retrospectively reviewed.

RESULTS

A total of 225 patients, mean age 12.8 ± 5.8 years, were identified. Target-of-interest (TOI) locations included extratemporal (44.4%), temporal neocortical (8.4%), mesiotemporal (23.1%), hypothalamic (14.2%), and callosal (9.8%). Visualase and NeuroBlate SLA systems were used in 199 and 26 cases, respectively. Procedure goals included ablation (149 cases), disconnection (63), or both (13). The mean follow-up was 27 ± 20.4 months. Improvement in targeted seizure type (TST) was seen in 179 (84.0%) patients. Engel classification was reported for 167 (74.2%) patients; excluding the palliative cases, 74 (49.7%), 35 (23.5%), 10 (6.7%), and 30 (20.1%) patients had Engel class I, II, III, and IV outcomes, respectively. For patients with a follow-up ≥ 12 months, 25 (51.0%), 18 (36.7%), 3 (6.1%), and 3 (6.1%) had Engel class I, II, III, and IV outcomes, respectively. Patients with a history of pre-SLA surgery related to the TOI, a pathology of malformation of cortical development, and 2+ trajectories per TOI were more likely to experience no improvement in seizure frequency and/or to have an unfavorable outcome. A greater number of smaller thermal lesions was associated with greater improvement in TST.

Thirty (13.3%) patients experienced 51 short-term complications including malpositioned catheter (3 cases), intracranial hemorrhage (2), transient neurological deficit (19), permanent neurological deficit (3), symptomatic perilesional edema (6), hydrocephalus (1), CSF leakage (1), wound infection (2), unplanned ICU stay (5), and unplanned 30-day readmission (9). The relative incidence of complications was higher in the hypothalamic target location. Target volume, number of laser trajectories, number or size of thermal lesions, or use of perioperative steroids did not have a significant effect on short-term complications.

CONCLUSIONS

SLA appears to be an effective and well-tolerated treatment option for children with DRE. Large-volume prospective studies are needed to better understand the indications for treatment and demonstrate the long-term efficacy of SLA in this population.

Free access

Cost-effectiveness of invasive monitoring strategies in epilepsy surgery

Taylor J. Abel, Nallammai Muthiah, Jasmine L. Hect, Jorge Gonzalez-Martinez, Afshin Salehi, Matthew D. Smyth, and Kenneth J. Smith

OBJECTIVE

Drug-resistant epilepsy occurs in up to 40% of patients with epilepsy who may be considered for epilepsy surgery. For drug-resistant focal epilepsy, up to 50% of patients require invasive monitoring prior to surgery. Of the most common invasive monitoring strategies (subdural electrodes [SDEs] and stereo-electroencephalography [sEEG]), the most cost-effective strategy is unknown despite substantial differences in morbidity profiles.

METHODS

Using data collected from an internationally representative sample published in available systematic reviews and meta-analyses, this economic evaluation study employs a decision analysis model to simulate the risks and benefits of SDE and sEEG invasive monitoring strategies. In this model, patients faced differing risks of morbidity, mortality, resection, and seizure freedom depending on which invasive monitoring strategy they underwent. A range of cost values was obtained from a recently published single-center cost-utility analysis. The model considers a base case simulation of a characteristic patient with drug-resistant epilepsy using clinical parameters obtained from systematic reviews of invasive monitoring available in the literature. The main outcome measure was the probability of a positive outcome after invasive monitoring, which was defined as improvement in seizures without a complication. Cost-effectiveness was measured using an incremental cost-effectiveness ratio (ICER).

RESULTS

Invasive monitoring with sEEG had an increased cost of $274 and increased probability of effectiveness of 0.02 compared with SDEs, yielding an ICER of $12,630 per positive outcome obtained. Sensitivity analyses varied parameters widely and revealed consistent model results across the range of clinical parameters reported in the literature. One-way sensitivity analyses revealed that invasive monitoring strategy costs were the most influential parameter for model outcome.

CONCLUSIONS

In this analysis, based on available observational data and estimates of complication costs, invasive monitoring with either SDEs or sEEG was nearly equivalent in terms of cost-effectiveness.

Free access

Impact of age at endoscopic metopic synostosis repair on anthropometric outcomes

Sarah N. Chiang, Erin C. Peterson, David C. Lauzier, Sean D. McEvoy, Gary B. Skolnick, Sybill D. Naidoo, Matthew D. Smyth, and Kamlesh B. Patel

OBJECTIVE

Endoscopic strip craniectomy for metopic craniosynostosis relies on rapid growth and postoperative helmeting for correction. Endoscopic repair is generally performed before patients reach 4 months of age, and outcomes in older patients have yet to be quantified. Here, the authors examined a cohort of patients treated with endoscopic repair before or after 4 months of age to determine aesthetic outcomes of delayed repairs.

METHODS

Data from eligible patients were retrospectively assessed and aggregated in a dedicated metopic synostosis database. Inclusion criteria were radiographically confirmed metopic synostosis and endoscopic treatment. Patients were dichotomized into two groups: those younger than 4 months and those 4 months or older at the time of repair. The frontal width and interfrontal divergence angle (IFDA) were measured on reconstructed CT images. These measurements, alongside operative time, estimated blood loss, and transfusion rates, were compared between groups using the Student t-test or chi-square test.

RESULTS

The study population comprised 28 patients treated before 4 months of age and 8 patients treated at 4–6 months of age. Patient sex and perioperative complications did not differ by age group. Older age at repair was not significantly associated with 1-year postoperative IFDA (140° ± 4.2° vs 142° ± 5.0°, p = 0.28) or frontal width (84 ± 5.2 vs 83 ± 4.4 mm, p = 0.47).

CONCLUSIONS

One-year postoperative IFDA and frontal width do not differ significantly between patients treated before and after 4 months of age. Further study with longer follow-up is necessary to confirm the longevity of these results at skeletal maturity.

Free access

A multi-institutional survey on calvarial vault remodeling techniques for sagittal synostosis and outcomes analysis for patients treated at 12 months and older

David Chi, Ella Gibson, Sarah N. Chiang, Koeun Lee, Sybill D. Naidoo, Amy Lee, Craig Birgfeld, Ian F. Pollack, Jesse Goldstein, Michael Golinko, Christopher M. Bonfield, Faizi A. Siddiqi, John R. W. Kestle, Matthew D. Smyth, Kamlesh B. Patel, and the Synostosis Research Group (SynRG)

OBJECTIVE

Surgical treatment of sagittal craniosynostosis is challenging in older patients. This study aimed to assess the effect of increasing age on open surgical technique selection and patient outcomes using the multi-institutional Synostosis Research Group (SynRG) collaboration.

METHODS

Surgeons in SynRG were surveyed for key influences on their preferred open calvarial vault remodeling techniques at various patient ages: < 6, 6–12, and > 12 months. The SynRG database was then queried for open repairs of nonsyndromic sagittal craniosynostosis performed for patients older than 12 months of age. Perioperative measures, complications, and preoperative and postoperative cephalic indices were reviewed.

RESULTS

All surgeons preferred to treat patients at an earlier age, and most (89%) believed that less-optimal outcomes were achieved at ages older than 12 months. The modified pi procedure was the dominant technique in those younger than 12 months, while more involved open surgical techniques were performed for older patients, with a wide variety of open calvarial vault remodeling techniques used. Forty-four patients met inclusion criteria, with a mean (± SD) age at surgery of 29 ± 16 months. Eleven patients underwent parietal reshaping, 10 parietal-occipital switch, 9 clamshell craniotomy, 7 geometric parietal expansion, 6 modified pi procedure, and 1 parietal distraction. There were no readmissions, complications, or mortality within 30 days postoperatively. Patients’ cephalic indices improved a mean of 6.4% ± 4.0%, with a mean postoperative cephalic index of 74.2% ± 4.9%. Differences in postoperative cephalic index (p < 0.04) and hospital length of stay (p = 0.01) were significant between technique cohorts. Post hoc Tukey-Kramer analysis identified the parietal reshaping technique as being significantly associated with a reduced hospital length of stay.

CONCLUSIONS

Patient age is an important driver in technique selection, with surgeons selecting a more involved calvarial vault remodeling technique in older children. A variety of surgical techniques were analyzed, with the parietal reshaping technique being significantly associated with reduced length of stay; however, multiple perioperative factors may be contributory and require further analysis. When performed at high-volume centers by experienced pediatric neurosurgeons and craniofacial surgeons, open calvarial vault techniques can be a safe method for treating sagittal craniosynostosis in older children.

Free access

Cranial vault imaging for pediatric head trauma using a radial VIBE MRI sequence

Kamlesh B. Patel, Cihat Eldeniz, Gary B. Skolnick, Paul K. Commean, Parna Eshraghi Boroojeni, Udayabhanu Jammalamadaka, Corinne Merrill, Matthew D. Smyth, Manu S. Goyal, and Hongyu An

OBJECTIVE

Head trauma is the most common indication for a CT scan. In this pilot study, the authors assess the feasibility of a 5-minute high-resolution 3D golden-angle (GA) stack-of-stars radial volumetric interpolated breath-hold examination (VIBE) MRI sequence (GA-VIBE) to obtain clinically acceptable cranial bone images and identify cranial vault fractures compared to CT.

METHODS

Patients younger than 18 years of age presenting after head trauma were eligible for the study. Three clinicians reviewed and assessed 1) slice-by-slice volumetric CT and inverted MR images, and 2) 3D reconstructions obtained from inverted MR images and the gold standard (CT). For each image set, reviewers noted on 5-point Likert scales whether they recommended that a repeat scan be performed and the presence or absence of cranial vault fractures.

RESULTS

Thirty-one patients completed MRI after a clinical head CT scan was performed. Based on CT imaging, 8 of 31 patients had cranial fractures. Two of 31 patients were sedated as part of their clinical MRI scan. In 30 (97%) of 31 MRI reviews, clinicians agreed (or strongly agreed) that the image quality was acceptable for clinical diagnosis. Overall, comparing MRI to acceptable gold-standard CT, sensitivity and specificity of fracture detection were 100%. Furthermore, there were no discrepancies between CT and MRI in classification of fracture type or location.

CONCLUSIONS

When compared with the gold standard (CT), the volumetric and 3D reconstructed images using the GA-VIBE sequence were able to produce clinically acceptable cranial images with excellent ability to detect cranial vault fractures.

Free access

Complications and outcomes of posterior fossa decompression with duraplasty versus without duraplasty for pediatric patients with Chiari malformation type I and syringomyelia: a study from the Park-Reeves Syringomyelia Research Consortium

S. Hassan A. Akbari, Alexander T. Yahanda, Laurie L. Ackerman, P. David Adelson, Raheel Ahmed, Gregory W. Albert, Philipp R. Aldana, Tord D. Alden, Richard C. E. Anderson, David F. Bauer, Tammy Bethel-Anderson, Karin Bierbrauer, Douglas L. Brockmeyer, Joshua J. Chern, Daniel E. Couture, David J. Daniels, Brian J. Dlouhy, Susan R. Durham, Richard G. Ellenbogen, Ramin Eskandari, Herbert E. Fuchs, Gerald A. Grant, Patrick C. Graupman, Stephanie Greene, Jeffrey P. Greenfield, Naina L. Gross, Daniel J. Guillaume, Todd C. Hankinson, Gregory G. Heuer, Mark Iantosca, Bermans J. Iskandar, Eric M. Jackson, George I. Jallo, James M. Johnston, Bruce A. Kaufman, Robert F. Keating, Nicklaus R. Khan, Mark D. Krieger, Jeffrey R. Leonard, Cormac O. Maher, Francesco T. Mangano, J. Gordon McComb, Sean D. McEvoy, Thanda Meehan, Arnold H. Menezes, Michael S. Muhlbauer, Brent R. O’Neill, Greg Olavarria, John Ragheb, Nathan R. Selden, Manish N. Shah, Chevis N. Shannon, Joshua S. Shimony, Matthew D. Smyth, Scellig S. D. Stone, Jennifer M. Strahle, Mandeep S. Tamber, James C. Torner, Gerald F. Tuite, Elizabeth C. Tyler-Kabara, Scott D. Wait, John C. Wellons III, William E. Whitehead, Tae Sung Park, and David D. Limbrick Jr.

OBJECTIVE

The aim of this study was to determine differences in complications and outcomes between posterior fossa decompression with duraplasty (PFDD) and without duraplasty (PFD) for the treatment of pediatric Chiari malformation type I (CM1) and syringomyelia (SM).

METHODS

The authors used retrospective and prospective components of the Park-Reeves Syringomyelia Research Consortium database to identify pediatric patients with CM1-SM who received PFD or PFDD and had at least 1 year of follow-up data. Preoperative, treatment, and postoperative characteristics were recorded and compared between groups.

RESULTS

A total of 692 patients met the inclusion criteria for this database study. PFD was performed in 117 (16.9%) and PFDD in 575 (83.1%) patients. The mean age at surgery was 9.86 years, and the mean follow-up time was 2.73 years. There were no significant differences in presenting signs or symptoms between groups, although the preoperative syrinx size was smaller in the PFD group. The PFD group had a shorter mean operating room time (p < 0.0001), fewer patients with > 50 mL of blood loss (p = 0.04), and shorter hospital stays (p = 0.0001). There were 4 intraoperative complications, all within the PFDD group (0.7%, p > 0.99). Patients undergoing PFDD had a 6-month complication rate of 24.3%, compared with 13.7% in the PFD group (p = 0.01). There were no differences between groups for postoperative complications beyond 6 months (p = 0.33). PFD patients were more likely to require revision surgery (17.9% vs 8.3%, p = 0.002). PFDD was associated with greater improvements in headaches (89.6% vs 80.8%, p = 0.04) and back pain (86.5% vs 59.1%, p = 0.01). There were no differences between groups for improvement in neurological examination findings. PFDD was associated with greater reduction in anteroposterior syrinx size (43.7% vs 26.9%, p = 0.0001) and syrinx length (18.9% vs 5.6%, p = 0.04) compared with PFD.

CONCLUSIONS

PFD was associated with reduced operative time and blood loss, shorter hospital stays, and fewer postoperative complications within 6 months. However, PFDD was associated with better symptom improvement and reduction in syrinx size and lower rates of revision decompression. The two surgeries have low intraoperative complication rates and comparable complication rates beyond 6 months.