Essential tremor (also called familial tremor or benign essential tremor) is a common movement disorder. In fact, it is six times more common than Parkinson’s disease. It is...
The best way to proceed here would be first to see your doctor to obtain a full history and neurologic exam. If neurologic deficits are found (weakness, sensory loss, etc.), then imaging studies (CT/MR scans) might be appropriate.
But the simple answer to your question is a lumbar spine injury would not cause problems with the hands.
Sometimes, however, abnormally large heads can be indicative of serious problems such has hydrocephalus or other problems inside the skull. Since most pregnancies nowadays include fetal ultrasounds, I'm assuming that the doctors knew that the ultrasounds did not show any problems such as hydrocephalus inside the skull.
Signs that would be worrisome are: 1. If the head growth after birth is abnormally rapid (pediatricians routinely measure head size on well baby visits and chart them comparing to normal sizes. 2. If the fontanelle (soft spot on the top of the babies head) is bulging or tense. 3. If there are other neurologic signs such as excessive irritability, delayed development of normal milestones, seizures, crossed eyes.
Bottom line: It is likely that the head size is not of serious consequences, but a full discussion with your pediatrician is appropriate because of the concerns that sometimes a large head size (especially if the head growth is abnormally rapid) can indicate a serious problem which needs prompt attention.
Often, the appearance on the MRI scan is highly suggestive of whether or not a tumor is benign or malignant, but in some cases, it is necessary to obtain a biopsy to be sure.
For some tumors, the appropriate next step is surgery to biopsy and remove it. For other cases, it may be appropriate to biopsy only. For other patients, radiosurgery (a form of radiation therapy) may be appropriate without surgery. Finally, in some patients, doctors recommend no treatment, but merely follow up scans from time to time.
All these decisions depend on details of what was found on the MRI scan and what the other medical issues are with the patient.
However, in most patients, the herniated disk may cause only pain (especially in the leg) -- if there is no weakness, or bowel/bladder incontinence, surgery can often be avoided and the pain treated with analgesics, exercise, weight loss and time.
So short answer: unlikely that back pain alone causes paralysis, but things which cause back pain (like tumors/infections of the spine) can lead to neurologic problems. In terms of percentages, the vast majority of chronic back pain does not lead to paralysis, but on rare occasions neurologic damage can occur.