A Case-controlled Investigation of Pain Experience and Sensory Function in Neuronal Ceroid Lipofuscinosis

Identifying and treating CLN3 disease outside the central nervous system

CLN3 disease causes profound neurological deficits in affected children, but less well recognized are a variety of peripheral neuromuscular and gastrointestinal problems. We hypothesized that in addition to central nervous system (CNS) degeneration, CLN3 deficiency may also directly affect neuronal and/or glial cell populations in the rest of the body. Therefore, we examined the neuromuscular and enteric nervous system in Cln3 Δex7/8 mice. There was no overt sciatic nerve axon loss or demyelination in Cln3 Δex7/8 mice, but significant loss of terminal Schwann cells (tSCs) at lower limb neuromuscular junctions (NMJ), and progressive NMJ denervation. This was accompanied by pronounced myofiber atrophy, with fewer and displaced myofibril nuclei, with similar pathology seen in a human CLN3 muscle biopsy. Atrophy was also evident in bowel smooth muscle with Cln3 Δex7/8 mice displaying slow bowel transit, and significant loss of both enteric neurons and glial cells throughout the bowel. Similar enteric pathology was evident at autopsy in the small intestine and colon of a human CLN3 case. Neonatal administration of intravenous gene therapy to Cln3 Δex7/8 mice using an AAV9-hCLN3 vector completely prevented tSCs and NMJ pathology, atrophy of both skeletal and smooth muscle, positively impacted bowel transit and largely prevented the loss of enteric neurons and glia. These findings reveal an underappreciated, but profound, impact of CLN3 disease outside the CNS and suggest these novel aspects of disease may be treatable using gene therapy.

Graphical abstract

Behaviours and psychological symptoms of childhood dementia: two cases of psychosocial interventions

Childhood dementias are a group of rare, fatal neurodegenerative disorders, characterised by global cognitive decline, loss of previously acquired developmental skills and behaviours and psychological symptoms of dementia (BPSD). Batten disease, or neuronal ceroid lipofuscinosis, and Sanfilippo syndrome, or mucopolysaccharidosis type III, are two of the more common forms of childhood dementia disorders worldwide. While psychosocial interventions are the best available therapeutic approach for BPSD management in adult-onset dementia, there is very limited literature or clinical experience in the context of childhood dementia. To address this gap, we conducted a descriptive case analysis of BPSD profiles, associated contributing factors and targeted psychosocial interventions in two cases with childhood dementia disorders (Sanfilippo syndrome and CLN3 (juvenile onset) Batten disease) who were referred to Dementia Support Australia, a national dementia behaviour support service in Australia. Primary BPSD identified in these disorders included physical and verbal aggression and irritability/lability. In these cases, contributing factors to the development of BPSD were not monolithic, encompassing pain, caregiver's approach and over or under-stimulation. Improvement in BPSD were observed using the Neuropsychiatric Inventory-Quesionnaire and globally noted as per the qualitative feedback reported by family and caregivers. Person-centred, multimodal psychosocial interventions were recognised as effective therapies in resolving BPSD in these cases. In conclusion, the case studies described the nature and presentation of BPSD in two common forms of childhood dementia and demonstrated the potential benefits of person-centred psychosocial interventions (delivered through national dementia-specific support programs) in alleviating BPSD such as irritability and aggression in these disorders.

Developmental Skills and Neurorehabilitation for Children With Batten Disease: A Retrospective Chart Review of a Comprehensive Batten Clinic

BACKGROUND

Batten disease is a rare, progressive neurogenetic disorder composed of 13 genotypes that often presents in childhood. Children present with seizures, vision loss, and developmental regression. Neurorehabilitation services (i.e., physical therapy, occupational therapy, and speech-language therapy) can help improve the quality of life for children and their families. Owing to the rarity of Batten disease, there are no standardized clinical recommendations or outcome assessments. To describe developmental profiles, current dose of neurorehabilitation, and outcome assessments used clinically for children diagnosed with Batten disease.

METHODS

Electronic medical records of 70 children with Batten disease (subtypes n = 5 CLN1; n = 25 CLN2; n = 23 CLN3; n = 17 CLN6) were reviewed (7.0 ± 3.4 years). Descriptive statistics were used to describe clinical features, developmental skills, dose of neurorehabilitation, and outcome assessment use.

RESULTS

Across CLN subtypes, most children experienced vision impairments (61%) and seizures (68%). Most children demonstrated delays in fine motor (65%), gross motor (80%), cognitive (63%), and language skills (83%). The most common frequency of neurorehabilitation was weekly (42% to 43%). Two standardized outcome assessments were used to track developmental outcomes: Peabody Developmental Motor Scales, second edition (30% of children completed this assessment) and Preschool Language Scales, fifth edition (27.4% of children completed this assessment).

CONCLUSIONS

Neurorehabilitation professionals should understand the clinical features and prognosis for children with Batten disease. The child's clinical features and family preferences should guide the rehabilitation plan of care. Future work needs to be completed to define dosing parameters and validate outcome assessments for neurorehabilitation services.

Treatment of non-epileptic episodes of anxious, fearful behavior in adolescent juvenile neuronal ceroid lipofuscinosis (CLN3 disease)

Background

Recurrent non-epileptic episodes of frightened facial and body expression occur in more than half of post-adolescent patients with juvenile neuronal ceroid lipofuscinosis (JNCL, CLN3 disease). Clinically, the episodes look similar to the attacks of paroxysmal sympathetic hyperactivity (PSH) commonly seen following traumatic brain injury (TBI). The episodes occur when the patients are exposed to separation, hear loud sounds or are otherwise bothered by discomfort and as in PSH following TBI, the attacks are difficult to prevent and/or treat.

Aim and methods

Based on present knowledge of triggering factors, the neural anxiety/fear circuit, its afferent and efferent pathways and documented CLN3 disease-impact on these tracks, the current study discusses a rational approach how to prevent and/or treat the attacks.

Results

Patients with JNCL have a disturbed somatosensory modulation leading to a reduced threshold of pain; a degeneration within the neural anxiety/fear circuit leading to an imbalance of central network inhibition and excitation pathways; and finally, an, with advancing age, increasing autonomic imbalance leading to a significant dominance of the sympathetic neural system.

Discussion

Theoretically, there are three points of attack how to prevent or treat the episodes: (1) increase in threshold of discomfort impact; (2) modulation of imbalance of central network inhibition and excitation, and (3) restoring the balance between the sympathetic and parasympathetic neural systems prompted by a parasympathetic withdrawal. As to (1) and (2), prevention should have the greatest priority. As regards (3), research of transcutaneous vagal stimulation treatment in JNCL is warranted.

Clinical management and diagnosis of CLN2 disease: consensus of the Brazilian experts group

Neuronal ceroid lipofuscinosis type 2 (CLN2) is a rare neurodegenerative genetic disease that affects children in early life. Its classic form is rapidly progressive, leading to death within the first 10 years. The urge for earlier diagnosis increases with the availability of enzyme replacement therapy. A panel of nine Brazilian child neurologists combined their expertise in CLN2 with evidence from the medical literature to establish a consensus to manage this disease in Brazil. They voted 92 questions including diagnosis, clinical manifestations, and treatment of the disease, considering the access to healthcare in this country. Clinicians should suspect CLN2 disease in any child, from 2 to 4 years old, with language delay and epilepsy. Even though the classic form is the most prevalent, atypical cases with different phenotypes can be found. Electroencephalogram, magnetic resonance imaging, molecular and biochemical testing are the main tools to investigate and confirm the diagnosis. However, we have limited access to molecular testing in Brazil, and rely on the support from the pharmaceutical industry. The management of CLN2 should involve a multidisciplinary team and focus on the quality of life of patients and on family support. Enzyme replacement therapy with Cerliponase α is an innovative treatment approved in Brazil since 2018; it delays functional decline and provides quality of life. Given the difficulties for the diagnosis and treatment of rare diseases in our public health system, the early diagnosis of CLN2 needs improvement as enzyme replacement therapy is available and modifies the prognosis of patients.

Etiology of anxious and fearful behavior in juvenile neuronal ceroid lipofuscinosis (CLN3 disease)

Background

Juvenile neuronal ceroid lipofuscinosis (JNCL, CLN3) is a childhood-onset neurodegenerative disease with prominent symptoms comprising a pediatric dementia syndrome. As in adult dementia, behavioral symptoms like mood disturbances and anxiety are common. In contrast to in adult dementia, however, the anxious behavioral symptoms increase during the terminal phase of JNCL disease. In the present study, the current understanding of the neurobiological mechanisms of anxiety and anxious behavior in general is addressed as will a discussion of the mechanism of the anxious behavior seen in young JNCL patients. Based on developmental behavioral points of view, known neurobiological mechanisms, and the clinical presentation of the anxious behavior, a theory of its etiology is described.

Result and discussion

During the terminal phase, the cognitive developmental age of JNCL patients is below 2 years. At this stage of mental development individuals act primarily from a concrete world of consciousness and do not have the cognitive ability to encounter a normal anxiety response. Instead, they experience the evolutionary basic emotion of fear, and as the episodes typically are provoked when the adolescent JNCL patient is exposed to either loud sounds, is lifted from the ground, or separated from the mother/known caregiver, the fear can best be perceived as the developmental natural fear-response that appears in children 0-2 years of age. The efferent pathways of the neural fear circuits are mediated through autonomic, neuroendocrine, and skeletal-motor responses. The autonomic activation occurs early, is mediated through the sympathetic and parasympathetic neural systems, and as JNCL patients beyond puberty have an autonomic imbalance with a significant sympathetic hyperactivity, the activation of the autonomic nervous system results in a disproportionate high sympathetic activity resulting in tachycardia, tachypnea, excessive sweating, hyperthermia, and an increased atypical muscle activity. The episodes are thus phenotypically similar to what is seen as Paroxysmal Sympathetic Hyperactivity (PSH) following an acute traumatic brain injury. As in PSH, treatment is difficult and so far, no consensus of a treatment algorithm exists. Use of sedative and analgesic medication and minimizing or avoiding provocative stimuli may partly reduce the frequency and intensity of the attacks. Transcutaneous vagal nerve stimulation might be an option worth to investigate rebalancing the sympathetic-parasympathetic disproportion.

Unique Pain Responses in Different Etiological Subgroups of Intellectual and Developmental Disabilities

We studied whether there exist variations in pain responses between different intellectual and developmental disability (IDD) etiologies. Self-reports and facial expressions (Facial Action Coding System = FACS) were recorded during experimental pressure stimuli and compared among 31 individuals with IDD-13 with cerebral palsy (CP), nine with Down syndrome (DS), nine with unspecified origin (UIDD)-and among 15 typically developing controls (TDCs). The CP and DS groups had higher pain ratings and FACS scores compared to the UIDD and TDC groups, and steeper stimulus-response functions. The DS group exhibited the most diverse facial expressions. There were variations in the foci of facial expressions between groups. It appears that different IDD etiologies display distinct pain responses.

Pain Behavior of People with Intellectual and Developmental Disabilities Coded with the New PAIC-15 and Validation of Its Arabic Translation

Pain management necessitates assessment of pain; the gold standard being self-report. Among individuals with intellectual and developmental disabilities (IDD), self-report may be limited and therefore indirect methods for pain assessment are required. A new, internationally agreed upon and user-friendly observational tool was recently published—the Pain Assessment in Impaired Cognition (PAIC-15). The current study’s aims were: to test the use of the PAIC-15 in assessing pain among people with IDD and to translate the PAIC-15 into Arabic for dissemination among Arabic-speaking professionals. Pain behavior following experimental pressure stimuli was analyzed among 30 individuals with IDD and 15 typically developing controls (TDCs). Translation of the PAIC followed the forward–backward approach; and reliability between the two versions and between raters was calculated. Observational scores with the PAIC-15 exhibited a stimulus–response relationship with pressure stimulation. Those of the IDD group were greater than those of the TDC group. The overall agreement between the English and Arabic versions was high (ICC = 0.89); single items exhibited moderate to high agreement levels. Inter-rater reliability was high (ICC = 0.92). Both versions of the PAIC-15 are feasible and reliable tools to record pain behavior in individuals with IDD. Future studies using these tools in clinical settings are warranted.

Management of CLN1 Disease: International Clinical Consensus

BACKGROUND

CLN1 disease (neuronal ceroid lipofuscinosis type 1) is a rare, genetic, neurodegenerative lysosomal storage disorder caused by palmitoyl-protein thioesterase 1 (PPT1) enzyme deficiency. Clinical features include developmental delay, psychomotor regression, seizures, ataxia, movement disorders, visual impairment, and early death. In general, the later the age at symptom onset, the more protracted the disease course. We sought to evaluate current evidence and to develop expert practice consensus to support clinicians who have not previously encountered patients with this rare disease.

METHODS

We searched the literature for guidelines and evidence to support clinical practice recommendations. We surveyed CLN1 disease experts and caregivers regarding their experiences and recommendations, and a meeting of experts was conducted to ascertain points of consensus and clinical practice differences.

RESULTS

We found a limited evidence base for treatment and no clinical management guidelines specific to CLN1 disease. Fifteen CLN1 disease experts and 39 caregivers responded to the surveys, and 14 experts met to develop consensus-based recommendations. The resulting management recommendations are uniquely informed by family perspectives, due to the inclusion of caregiver and advocate perspectives. A family-centered approach is supported, and individualized, multidisciplinary care is emphasized in the recommendations. Ascertainment of the specific CLN1 disease phenotype (infantile-, late infantile-, juvenile-, or adult-onset) is of key importance in informing the anticipated clinical course, prognosis, and care needs. Goals and strategies should be periodically reevaluated and adapted to patients' current needs, with a primary aim of optimizing patient and family quality of life.

Guidelines on the diagnosis, clinical assessments, treatment and management for CLN2 disease patients

Background

CLN2 disease (Neuronal Ceroid Lipofuscinosis Type 2) is an ultra-rare, neurodegenerative lysosomal storage disease, caused by an enzyme deficiency of tripeptidyl peptidase 1 (TPP1). Lack of disease awareness and the non-specificity of presenting symptoms often leads to delayed diagnosis. These guidelines provide robust evidence-based, expert-agreed recommendations on the risks/benefits of disease-modifying treatments and the medical interventions used to manage this condition.

Methods

An expert mapping tool process was developed ranking multidisciplinary professionals, with knowledge of CLN2 disease, diagnostic or management experience of CLN2 disease, or family support professionals. Individuals were sequentially approached to identify two chairs, ensuring that the process was transparent and unbiased. A systematic literature review of published evidence using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance was independently and simultaneously conducted to develop key statements based upon the strength of the publications. Clinical care statements formed the basis of an international modified Delphi consensus determination process using the virtual meeting (Within3) online platform which requested experts to agree or disagree with any changes. Statements reaching the consensus mark became the guiding statements within this manuscript, which were subsequently assessed against the Appraisal of Guidelines for Research and Evaluation (AGREEII) criteria.

Results

Twenty-one international experts from 7 different specialities, including a patient advocate, were identified. Fifty-three guideline statements were developed covering 13 domains: General Description and Statements, Diagnostics, Clinical Recommendations and Management, Assessments, Interventions and Treatment, Additional Care Considerations, Social Care Considerations, Pain Management, Epilepsy / Seizures, Nutritional Care Interventions, Respiratory Health, Sleep and Rest, and End of Life Care. Consensus was reached after a single round of voting, with one exception which was revised, and agreed by 100% of the SC and achieved 80% consensus in the second voting round. The overall AGREE II assessment score obtained for the development of the guidelines was 5.7 (where 1 represents the lowest quality, and 7 represents the highest quality).

Conclusion

This program provides robust evidence- and consensus-driven guidelines that can be used by all healthcare professionals involved in the management of patients with CLN2 disease and other neurodegenerative disorders. This addresses the clinical need to complement other information available.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01813-5.

Specific Behavioral Responses Rather Than Autonomic Responses Can Indicate and Quantify Acute Pain among Individuals with Intellectual and Developmental Disabilities

Individuals with intellectual and developmental disabilities (IDD) are at a high risk of experiencing pain. Pain management requires assessment, a challenging mission considering the impaired communication skills in IDD. We analyzed subjective and objective responses following calibrated experimental stimuli to determine whether they can differentiate between painful and non-painful states, and adequately quantify pain among individuals with IDD. Eighteen adults with IDD and 21 healthy controls (HC) received experimental pressure stimuli (innocuous, mildly noxious, and moderately noxious). Facial expressions (analyzed with the Facial Action Coding System (FACS)) and autonomic function (heart rate, heart rate variability (HRV), pulse, and galvanic skin response (GSR)) were continuously monitored, and self-reports using a pyramid and a numeric scale were obtained. Significant stimulus-response relationships were observed for the FACS and pyramid scores (but not for the numeric scores), and specific action units could differentiate between the noxious levels among the IDD group. FACS scores of the IDD group were higher and steeper than those of HC. HRV was overall lower among the IDD group, and GSR increased during noxious stimulation in both groups. In conclusion, the facial expressions and self-reports seem to reliably detect and quantify pain among individuals with mild-moderate IDD; their enhanced responses may indicate increased pain sensitivity that requires careful clinical consideration.

Investigating the Feasibility of a Modified Quantitative Sensory Testing Approach to Profile Sensory Function and Predict Pain Outcomes Following Intrathecal Baclofen Implant Surgery in Cerebral Palsy

OBJECTIVES

Intrathecal baclofen (ITB) pumps used to manage spasticity in children with cerebral palsy (CP) also improve pain outcomes for some but not all patients. The purpose of this clinical feasibility study was to explore whether a quantitative sensory testing approach could a) be modified and used to subgroup individuals into sensory profiles and b) test whether the profiles were related to postimplant pain outcomes (i.e., pain responsive or pain persistent).

SUBJECTS

A purposeful clinical sample of nine children with CP (mean age = 12.5 years, male = 56%) and complex communication needs participated.

METHODS

A prospective within-subject design was used to measure proxy-reported pain before and after ITB implant. Pain response status was determined by proxy-reported pain intensity change (>50% change in maximum rated intensity). A modified quantitative sensory testing (mQST) procedure was used to assess behavioral responsivity to an array of calibrated sensory (tactile/acute nociceptive) stimuli before surgery.

RESULTS

Seven individuals with presurgical pain had mQST differentiated sensory profiles in relation to ITB pain outcomes and relative to the two individuals with no pain. Presurgically, the ITB pain responsive subgroup (N = 3, maximum rated pain intensity decreased >50% after ITB implant) showed increased behavioral reactivity to an acute nociceptive stimulus and cold stimulus, whereas the ITB pain persistent subgroup (N = 4) showed reduced behavioral reactivity to cold and repeated von Frey stimulation relative to the no pain individuals.

CONCLUSION

Implications for patient selection criteria and stratification to presurgically identify individuals with CP "at risk" for persistent postprocedure pain are discussed.

Utility of lacrimal caruncle infrared thermography when monitoring alterations in autonomic activity in healthy humans

PURPOSE

Physiological markers that estimate sympathetic activation may be used to infer pain and stress in humans. To date, effective reproducible methods are invasive and pose an undesired risk to participants. Previous work in animal models has used infrared thermography to measure the temperature of the lacrimal caruncle region and may be a promising method for measuring stress and pain non-invasively. The current study aimed to determine whether this method is useful in humans.

METHODS

Sixteen young healthy participants (age: 18-35) were recruited and underwent sympathetic activation using a cold pressor test (CPT) and a muscle chemoreflex (MCR), and completed a control trial. Throughout all trials, infrared thermographic imaging of the lacrimal caruncle, heart rate, heart rate variability, mean arterial blood pressure and pulse transit time were measured.

RESULTS

Heart rate (MCR: 4 ± 3 bpm, CPT: 17 ± 4 bpm p < 0.01) and mean arterial pressure increased (MCR: 6 ± 2, CPT: 5 ± 2 mmHg, p < 0.01) and pulse transit time decreased (p = 0.03) with both sympathetic activation interventions. However, lacrimal caruncle temperature did not vary under any condition remaining at 35.2 ± 0.2 °C which was similar to baseline.

CONCLUSIONS

Our findings suggest infrared thermographic monitoring of eye temperature in humans does not reliably relate to sympathetic activation. This could be due to hemodynamic responses at the lacrimal caruncle that may be more complex than previously proposed with sympathetic activation. Alternatively, pulse transit time seems like a promising non-invasive measure of changes in sympathetic activation in humans.

Pain Measurement through Temperature Changes in Children Undergoing Dental Extractions

Background and Objective. Pain evaluation in children can be a difficult task, since it possesses sensory and affective components that are often hard to discriminate. Infrared thermography has previously been used as a diagnostic tool for pain detection in animals; therefore, the aim of this study was to assess the presence of temperature changes during dental extractions and to evaluate its correlation with heart rate changes as markers of pain and discomfort. Methods. Thermographic changes in the lacrimal caruncle and heart rate measurements were recorded in healthy children scheduled for dental extraction before and during the procedure and compared. Afterwards, correlation between temperature and heart rate was assessed. Results. We found significant differences in temperature and heart rate before the procedure and during the dental extraction (mean difference 4.07°C, p < 0.001, and 18.11 beats per minute, p < 0.001) and no evidence of correlation between both measurements. Conclusion. Thermographic changes in the lacrimal caruncle can be detected in patients who undergo dental extractions. These changes appear to be stable throughout time and to possess very little intersubject variation, thus making them a candidate for a surrogate marker of pain and discomfort. Future studies should be performed to confirm this claim.